bluuebunny/crossref_metadata_2025 huggingface dataset:
Atomic Layer Deposition of Ta2O5 Using the TaI5 and O2 Precursor Combination
Authors: Sundqvist J. , Högberg H. , Hårsta A.
Published: October 2003

Thin films of tantalum oxide have been deposited on Si(100) substrates using atomic layer deposition (ALD) employing the TaI5 and O2 precursor combination. Growth was studied in the temperature region 400 to 700 °C. The resulting films were found to be iodine‐free above 450 °C, and consisted of the polycrystalline orthorhombic β‐Ta2O5 phase. The growth rate was found to be strongly dependent on the deposition temperature, reaching a maximum of 0.17 nm cycle–1 at 600 °C.
Growth and Properties of TiCl4‐Derived CVD Titanium Oxide Films at Different CO2/H2 Inputs
Authors: Kuo D.‐H. , Shueh C.‐N.
Published: October 2003

Crystalline titanium oxide films with a thickness of 0.09–0.55 μm were prepared at temperatures below 500 °C by CVD using a mixture of titanium tetrachloride (TiCl4), carbon dioxide (CO2), and hydrogen (H2) as reactants. Film thickness decreased with increasing substrate temperature and CO2/H2 input. Nanosized microstructure was obtained at high CO2/H2 input due to the growth retardation of reacted HO‐TiCl3* by the unreacted TiCl4 and CO2. That film composition, i.e., the O/Ti ratio, increased with temperature and the CO2/H2 input can be explained by growth kinetics. Unlike film thickness, internal film stress increased with increasing substrate temperature. Adhesion was controlled by compressive internal stress due to the weak bonding between film and substrate. Two growth mechanisms are proposed to explain the tensile and compressive stress states in films produced by CVD. The adsorption‐controlled reaction has a film in compressive stress that increases with an increase in temperature. On the other hand, thermally activated CVD produces a film in tensile stress that decreases with an increase in substrate temperature.
Substrate‐Independent Palladium Atomic Layer Deposition
Authors: Senkevich J.J. , Tang F. , Rogers D. , Drotar J.T. , Jezewski C. , Lanford W.A. , Wang G.‐C. , Lu T.‐M.
Published: October 2003

A novel method is presented for the atomic layer deposition (ALD) of palladium on a tetrasulfide self‐assembled monolayer functionalized SiO2 surface. Additionally, a novel reducing agent (glyoxylic acid) was used to remove the organic ligands from the chemisorbed palladium(II) hexafluoroacetylacetonate metallorganic. Glyoxylic acid is an effective reducing agent above 200 °C, which is not optimal for palladium but it is effective enough to show proof‐of‐concept and deposit a Pd “seed” layer. Palladium was also deposited on iridium at 80 °C and 130 °C via a hydrogen process or on the Pd seed layer at 80 °C. The 60 Å Pd film grown on the tetrasulfide self‐assembled monolayer (SAM) showed nearly random texture and higher carbon and fluorine contamination levels compared to the one grown on Ir. The 55 Å film grown on Ir at 80 °C is highly (111) textured with a grain size of ∼60 Å, as shown by reflection high energy electron diffraction (RHEED). The higher contamination levels of the Pd film deposited on the tetrasulfide SAM, as measured by X‐ray photoelectron spectroscopy (XPS), is attributed to the high temperatures needed to deposit the Pd seed layer. The higher deposition temperatures cause more dissociation of the hfac ligand and a higher metallorganic desorption rate. These equate to less Pd being deposited and with higher contamination levels.
Pulsed Injection MOCVD of YSZ Thin Films onto Dense and Porous Substrates
Authors: Garcia G. , Caro J. , Santiso J. , Pardo J.A. , Figueras A. , Abrutis A.
Published: October 2003

In this work, we describe the preparation of YSZ layers on dense and porous substrates using the pulsed injection metal–organic (MO) CVD technique. In this technique, the vapor phase is obtained by injecting micro‐droplets of a solution, consisting of the required amounts of Zr(tmhd)4 and Y(tmhd)3 precursors in monoglyme, into a heated evaporator. The droplet characteristics (volume, precursor concentration, and injection frequency) were studied in order to control the growth rate and the microstructure of the layers. The optimum deposition parameters needed to achieve dense film microstructure on dense substrates were determined. For these optimized experimental conditions, we evaluated the growth rate of the layers as a function of temperature. The activation energy in the kinetically limited regime was found to be 96 kJ mol–1. The structure of the layers was analyzed as a function of the film composition. A concentration of 11 mol‐% of yttria fully stabilizes the cubic phase. This process has been applied to the preparation of dense YSZ membranes on porous substrates in order to use the YSZ layer as a solid electrolyte (SE) in electrochemical devices such as solid oxide fuel cells (SOFC), oxygen sensors, and generators. Dense YSZ layers were obtained on samples of porous alumina, and on YSZ‐Ni cermets. Characterization by scanning electron microscopy (SEM) and X‐ray diffraction (XRD) showed no cracks or voids along the grain boundaries, nor secondary phases due to chemical interaction with the substrate.
Theoretical Investigation of the Gas‐Phase Decomposition of Ga(N3)2Et as a Model for a Single‐Molecule GaN Precursor
Authors: Wolbank B. , Schmid R.
Published: October 2003

Density functional theory‐type calculations have been used to investigate possible decomposition pathways of the gallium azide Ga(N3)2Et, which served as a model for the working single‐molecule precursor Ga(N3)2[(CH2)3NMe2] (BAZIGA). Both kinetics and thermodynamics of radical and non‐radical reactions have been considered, focusing especially on the entropic effects at elevated temperatures. The β‐hydrogen elimination was found to be kinetically favored over the elimination of molecular nitrogen from the azide ligands. However, due to the strong entropic contributions that are able to compensate for bond energies, homolytic bond cleavage was calculated to be more facile than any non‐radical rearrangement reaction. A two‐step radical decomposition mechanism leading to the monoazide GaN3 (consistent with the available experimental results) is proposed.
Growth Per Cycle in Atomic Layer Deposition: A Theoretical Model
Authors: Puurunen R.L.
Published: October 2003

Atomic layer deposition (ALD) is used in advanced applications where thin layers of materials with precise thickness down to the nanometer scale are needed. Growth of materials by ALD takes place through repeating the separate, saturating reactions of at least two gaseous reactants with a solid substrate. When surface saturation is systematically utilized, the growth obtained per ALD reaction cycle is a well‐defined quantity that depends on i) the reactants used, ii) the ALD processing temperature, and iii) sometimes the substrate material. A model is derived to describe the growth per cycle in ALD as a function of the chemistry of the growth when compounds are used as reactants. Two main types of chemisorption may occur: i) ligand exchange reaction of the MLn reactant with surface “a” groups, where ligands are removed from the surface as gaseous aL, and ii) dissociation or association, where all parts of the MLn reactant are attached to the surface. A simple mathematical model based on the mass balance of chemisorption relates the growth per cycle to the size of the MLn reactant and the chemisorption mechanisms involved. Steric hindrance of the ligands causes saturation of chemisorption if a limited number of bonding sites does not cause it. Because of the steric hindrance, the growth per cycle remains less than a monolayer. The applicability of the model is illustrated through several theoretical examples.
Antibodies against human cell receptors, CD36, CD41a, and CD62P crossreact with porcine platelets
Authors: Delgado Angel V. , Alexander Stefan L. , McManus Albert T. , Pusateri Anthony E.
Published: October 2003

Background

A limitation in platelet study has been the availability of platelet function–specific membrane receptor antibodies for use in the various animal species that are currently used in the study of hemostasis and other phenomena.

Methods

Platelets were isolated from human and porcine blood. Resting and activated platelets were incubated with antibodies against the human cell surface receptors CD36 (clone CB38), CD41a (clone HIP8), CD62P (clone AK4), and CD63 (clone H5C6). Antibody titration and ligand blocking studies also were performed.

Results

Binding of anti‐CD41a and anti‐CD62P were similar for human and porcine platelets in percentage of platelets labeled and in number of receptors per cell. Binding of anti‐CD36 was similar between species, with fewer receptors present in porcine cells. Anti‐CD63 and anti‐CD107a did not bind specifically to porcine platelets.

Conclusion

The anti‐CD36, anti‐CD41a, and anti‐CD62P antibodies studied crossreact with porcine platelets and will be useful in the investigation of platelet function in porcine models. Cytometry Part B (Clin. Cytometry) 56B:62–67, 2003. Published 2003 Wiley‐Liss, Inc.
Routine use of immunophenotype by flow cytometry in tissues with suspected hematological malignancies
Authors: Martínez Antoni , Aymerich Marta , Castillo Mireia , Colomer Dolors , Bellosillo Beatriz , Campo Elias , Villamor Neus
Published: October 2003

Background

Immunophenotype is an essential parameter in the diagnosis of hematological malignancies. Flow cytometry (FCM) is used in the analysis of bone marrow or peripheral blood samples but is less frequently used in the evaluation of tissue biopsies with suspected hematological malignancies. The aim of this study was to analyze the role of FCM in the diagnosis of biopsies from patients with a suspected hematological disorder.

Methods

A total of 422 consecutive biopsies were studied using standard morphology, immunohistochemistry (IHC), and FCM. Results of FCM were obtained in less than 3 h and were interpreted independently from morphology and IHC.

Results

A strong correlation between malignant disease and abnormal pattern of FCM was observed (218 of 250) with the exception of Hodgkin disease (P < 0.001). Overall, negative predictive value was 0.52 and positive predictive value was 1. Light chain restriction was observed in 182 of 201 B‐cell lymphoma and in 0 of 142 non–B‐cell disorders by FCM. In contrast, light chain pattern could only be evaluated in 38 of 91 cases by IHC. FCM allowed a rapid diagnosis of infrequent or high‐grade malignancies such as histiocytic sarcoma or T‐lymphoblastic lymphoma. The addition of FCM in the routine study of tissue biopsies facilitates the diagnosis of double pathology in five (1%) patients.

Conclusions

FCM is a fast and reliable methodology for phenotyping tissue samples, which easily detects infrequent hematological malignancies, disease‐specific phenotypes and clonality in B‐cell lymphomas. Moreover, the simultaneous recognition of different cell populations allows the diagnosis of composite cell lymphomas, or double pathologies. Cytometry Part B (Clin. Cytometry) 56B:8–15, 2003. © 2003 Wiley‐Liss, Inc.
Flow cytometry of GATA transcription factors
Authors: Miura Toshihiko , Yokoyama Hisayuki , Minegishi Naoko , Sasaki Takeshi , Kaku Mitsuo , Harigae Hideo
Published: October 2003

Background

Although GATA‐1 and GATA‐2 have been shown to play an important role in hematopoiesis, the expression levels of these GATA proteins in the targeted cell population of clinical samples have not been studied. We applied flow cytometry (FCM) to examine the expression levels of these GATA proteins in the selected subpopulation in heterogeneous blood cells.

Methods

Cells were treated with a fixing solution and methanol followed by staining with specific antibodies to GATA proteins in a permeabilizing solution. Immunofluorescence microscopy and Northern blot analysis using GATA‐1 and GATA‐2 transfected cell lines and various leukemic cell lines were used to confirm the specificity of this method. Subsequently, the method was applied in two‐parameter studies combining GATA expression with surface marker expression in clinical samples.

Results

The positive signals were specifically detected in transfected cells and leukemic cell lines by FCM in agreement with the results of Northern blot and immunofluorescence microscopy. The expression of these GATA factors in the targeted cell population was easily detectable by gating with lineage‐specific cell surface markers. When the expression of these GATA proteins was examined in glycophorin A‐positive cells in clinical samples, the level of GATA‐1 was markedly different among the samples.

Conclusions

This detection system is useful to evaluate the relative expression level of each GATA protein in the targeted cell population among heterogeneous cells, and the results suggest an aberrant expression of GATA factors in hematological diseases. Cytometry Part B (Clin. Cytometry) 56B:1–7, 2003. © 2003 Wiley‐Liss, Inc.
Automated red blood cell differential analysis on a multi‐angle light scatter/fluorescence hematology analyzer
Authors: Kim Young Ran , van't Oever Ronny , Landayan Marilou , Bearden James
Published: October 2003

Background

Most hematology analyzers today are capable of performing white blood cell differential analysis but only limited red blood cell (RBC) differential parameters are available. Because of incomplete morphological information on RBC abnormalities, 5–10% of samples in hematology laboratories routinely undergo smear review. A more complete automated RBC differential capability is desired.

Methods

Abbott CELL DYN 4000 analyzer was modified to perform three‐dimensional (3D) RBC differential analysis (RBC/diff) on cell‐by‐cell basis at 488 nm as well as at 633 nm. Immature RBCs and all nucleated cells are labeled with a fluorescent nuclear stain, prior to RBC/diff using light loss and forward scatter (FSC) signal or two FSC signals and a third side scatter signal, projecting the cytogram onto a precalibrated 3D surface containing grid lines of volume (V) and hemoglobin concentration (HC), to determine the V and HC of a cell. Abnormally shaped RBCs (AbnRBC) are quantitated by the distance of each event to the 3D surface. A total of 154 normal and 484 clinical samples with various hemoglobinopathies have been analyzed.

Results

The 3D cytogram and the bivariate distribution of V and HC of individual event provided information to extract quantitative data on V, HC, schistocytes, and AbnRBC of mature and immature RBCs. The accuracy level of the 3D data is difficult to assess because of the semiquantitative nature of smear review, the only available reference method.

Conclusions

The 3D RBC cytograms provide a wealth of morphologic information useful for diagnosis and treatment of patients. With powerful computer programs available today, it is evident that the rate of smear review can be significantly reduced as a result. Cytometry Part B (Clin. Cytometry) 56B:43–54, 2003. © 2003 Wiley‐Liss, Inc.
Pan B‐cell markers are not redundant in analysis of chronic lymphocytic leukemia (CLL)
Authors: Monaghan Sara A. , Peterson LoAnn C. , James Cathy , Marszalek Laura , Khoong Adela , Bachta Dina J. , Karpus William J. , Goolsby Charles L.
Published: October 2003

Background

The classic immunophenotype for chronic lymphocytic leukemia (CLL) is CD19+, restricted dim surface expression of kappa or lambda light chain, CD5+, CD23+, dim CD20+, negative FMC7, and negative CD79b. However, the necessity of assaying for all 3 pan B‐cell markers (CD20, FMC7, and CD79b) by flow cytometry has not been definitively documented for CLL.

Methods

Qualitative patterns and semi‐quantitative assessment of staining intensity for CD20, FMC7 and CD79b were performed in 70 cases with a current or prior diagnosis of CLL or CLL with increased prolymphocytes leukemia (CLL/PL). The concurrent morphology in 66 of 70 specimens was classified as typical CLL in 53 cases, CLL/PL in 10 cases, and large cell lymphoma in 3 cases.

Results

Forty percent of the cases varied from the characteristic immunophenotype by having moderate or bright staining of CD20 (36%), FMC7 (7%), and/or CD79b (18%). Discrepant qualitative staining patterns were found between FMC7 and CD20 (21%), CD20 and CD79b (15%), and CD79b and FMC7 (10%). Semiquantitative measurement of staining intensity showed little correlation between CD79b and CD20 or FMC7. Moderate correlation was seen between CD20 and FMC7. No correlation was observed between morphology and intensity of marker expression.

Conclusions

Variable patterns and intensity of staining were seen for FMC7, CD20, and CD79b in this cohort of CLL samples. Dim or negative staining was most consistently seen for FMC7 (93% of specimens). Although FMC7 staining intensity was moderately correlated with CD20, CD79b intensity was poorly correlated with either CD20 or FMC7, and thus, may provide some independent information. Cytometry Part B (Clin. Cytometry) 56B:30–42, 2003. © 2003 Wiley‐Liss, Inc.
Production of intracellular IL‐2, TNF‐α, and IFN‐γ by T cells in B‐CLL
Authors: Gallego A. , Vargas J. A. , Castejón R. , Citores M. J. , Romero Y. , Millán I. , Durántez A.
Published: October 2003

Background

Recent evidence indicates that the slowly expanding population of CD5+ B cells that characterizes B‐cell chronic lymphocytic leukemia (B‐CLL) could be related to defects in the response to cytokine produced by T cells that regulate apoptosis. We studied the intracellular expressions of interleukin‐2 (IL‐2), tumor necrosis factor‐α (TNF‐α), and interferon‐γ (IFN‐γ) in T‐helper 1 cells (Th1 response) of B‐CLL.

Methods

Peripheral blood mononuclear cells from 21 healthy individuals and purified T cells from 21 early‐stage and 15 late‐stage B‐CLL patients were activated with phorbol myristate acetate and ionomycin. The Th1 cytoplasmic cytokines were evaluated in CD4+ and CD8+ T cells by flow cytometry.

Results

The percentages of CD4+ and CD8+ T cells positive for IL‐2 were significantly lower in B‐CLL patients than in healthy individuals (P = 0.030 and 0.049, respectively). No significant differences in TNF‐α or IFN‐γ intracellular expressions were found between patients and healthy individuals. TNF‐α‐ and IFN‐γ–expressing CD8 T cells were disease stage dependent, being significantly higher in late‐stage patients (P < 0.001 for both cytokines).

Conclusions

Our present observations suggested that Th1 cytokines may be of major importance in the pathogenesis of B‐CLL. Cytometry Part B (Clin. Cytometry) 56B:23–29, 2003. © 2003 Wiley‐Liss, Inc.
Measurement of proliferation marker Ki67 in breast tumour FNAs using laser scanning cytometry in comparison to conventional immunocytochemistry
Authors: Zabaglo Lila , Ormerod Michael G. , Dowsett Mitch
Published: October 2003

Background

A variety of markers, including Ki67, estrogen receptors (ER), and progesterone receptors (PgR), are frequently measured in fine needle aspirates from human breast carcinomas. Previously, we demonstrated the use of laser scanning cytometry (LSC) for the measurement of Ki67, ER, and PgR in a human breast carcinoma cell line, MCF7 (21). In the present study, we investigated the expression of Ki67 in breast tumour fine needle aspirates (FNAs) using LSC and compared the results to the data obtained using conventional immunocytochemistry (ICC).

Methods

A total of 11 sets of cytospins of FNAs taken from breast tumours at various stages of tamoxifen treatment were used. For LSC, the cytospins were stained for Ki67 with fluorescein using immunofluorescence; the nuclei were counterstained with propidium iodide. A parallel set of cytospins was stained using horseradish peroxidase and diaminobenzidine and scored manually by conventional light microscopy.

Results

Values for Ki67 obtained using the LSC were generally lower than ICC scores. The changes in Ki67 measured by the LSC were almost all parallel to those obtained by manual scoring of immunocytochemical stains.

Conclusions

It should be possible to use LSC for the routine measurement of Ki67 marker in FNAs from human breast carcinomas. Cytometry Part B (Clin. Cytometry) 56B:55–61, 2003. © 2003 Wiley‐Liss, Inc.
Comparative measurement of spontaneous apoptosis in pediatric acute leukemia by different techniques
Authors: Savitskiy Valery P. , Shman Tatiana V. , Potapnev Michael P.
Published: October 2003

Background

To distinguish between subgroups of patients with acute leukemia, the rate of spontaneous (culture‐induced) apoptosis of leukemic cells was evaluated using five methods.

Methods

Leukemic cells (cells) from the bone marrow of children with acute lymphoblastic leukemia (ALL, n = 112) and acute myeloid leukemia (AML, n = 30) were cultured for 20 h in vitro. The level of apoptosis was detected by fluorescent microscopy after staining with acridine orange (AO) or by flow cytometry after staining using PI, JC‐1, the APO‐BRDU kit, or the AnnexinV‐FITC kit.

Results

ALL cells were significantly more sensitive to spontaneous apoptosis versus AML cells, as was detected by all methods. The least sensitive technique was apoptosis detection by sub‐G1‐peak/PI‐staining. No difference in the rate of apoptosis in cells was determined between T‐ and B‐lineage ALL patients. In patients with B‐lineage ALL, strong positive correlation existed between the level of cells with loss of mitochondrial membrane potential (JC‐1), chromatin condensation (AO), and externalization of phosphatidylserine (AnnexinV+PI+). The proportion of AnnexinV+PI– cells had no correlative link with any other apoptotic cell subpopulation.

Conclusions

We found different sensitivities of ALL and AML cells to undergoing spontaneous apoptosis in vitro. Detection of the early/intermediate, but not the late stage of apoptosis is of preferable for correct assignment of spontaneous apoptosis in pediatric acute leukemia. Cytometry Part B (Clin. Cytometry) 56B:16–22, 2003. © 2003 Wiley‐Liss, Inc.
Investigating Actinyl Oxo Cations by X‐ray Absorption Spectroscopy
Authors: Den Auwer Christophe , Simoni Eric , Conradson Steven , Madic Charles
Published: October 2003

Early actinide elements (from U to Am) have the ability to form lineartrans‐dioxo complexes with formal valence of the actinide being equal to (V) or (VI). For instance, the ubiquity of the uranyl cation in uranium aqueous chemistry is the basis for its very important industrial and environmental concerns. As a result, the physical chemistry of the actinyl moieties has been the subject of constantly growing investigations. Among all the spectroscopic probes, X‐ray absorption spectroscopy is a particularly useful element and energy‐selective technique. This article reviews the investigation of molecular actinyl complexes using both XANES and EXAFS tools. The absorption edge features have long been used to characterize the frontier orbitals of the absorbing atom. In the case of actinide cations, the LIIIedge, located in the hard X‐ray region, provides a useful fingerprint of the cation polyhedron. Tentatively, simple molecular orbital considerations together with full multiple scattering simulation codes have provided significant interpretations of the edge features. Various examples involving a distortion of the actinyl coordination sphere, starting from the aqueous species are given. Complementary structural data can be obtained in the EXAFS region of the absorption spectrum. In the literature, such molecular systems have been well documented from uranyl aqueous chemistry to neptunyl or plutonyl coordination complexes with oxygen donor ligands. Furthermore, complexation mechanisms upon absorption onto mineral surfaces have been increasingly investigated over the past few years. Overall, contribution of the XAS technique to a better understanding of the actinide bonding is demonstrated from various examples of the literature and the authors’ data. Importance of the simulation codes in order to better describe the absorption features is also strongly underlined. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Characterisation of (Arene)tricarbonylchromium Complexes Linked to Cationic Fe and Ru Derivatives and Studies of First Hyperpolarisabilities by Hyper‐Rayleigh Scattering
Authors: Garcia Maria Helena , Royer Sophie , Robalo Maria Paula , Dias Alberto Romão , Tranchier Jean‐Philippe , Chavignon René , Prim Damien , Auffrant Audrey , Rose‐Munch Françoise , Rose Eric , Vaissermann Jacqueline , Persoons André , Asselberghs Inge
Published: October 2003

In order to investigate the non‐linear optical properties, in particular second‐order effects of binuclear organometallic complexes, a series of new cationic binuclear [MCp(DPPE)N≡C−(spacer)−C≡C−C6H5Cr(CO)3]+[PF6]− compounds and mononuclear precursors [N≡C−(spacer)−C≡ C−C6H5Cr(CO)3] have been synthesised [where M = FeII or RuII; Cp = η5‐C5H5 and spacer = phenyl ring (C6H4), thiophene, (C4H2S), or bithiophene (C4H2S)2]. The Fe or Ru organometallic π‐donor fragments were linked by an extended π system to the acceptor Cr(CO)3 fragment. The effect of π back‐donation involving the second Fe or Ru metal centre and the π* orbitals of the N≡C‐coordinated group, was probed by the ν(N≡C) stretching bands on the IR spectra and also by NMR spectroscopic data. The planarity, largely due to the π‐electron resonance, found on the solid state structure of the mononuclear complex [N≡C−C6H5−C≡C−(η6‐C6H5)Cr(CO)3] (1Cr) determined by X‐ray diffraction [monoclinic system, P21/c space group, with a = 10.326(2) Å, b = 13.209(5) Å, c = 11.799(2) Å and Z = 4] emphasises the electronic effect of this building block. The significant values of first hyperpolarisability β determined by hyper‐Rayleigh scattering (HRS) indicate that the Fe containing compounds were more efficient on second‐order non‐linear optical properties than the ruthenium analogues and the parent mononuclear chromium compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Novel Water‐Soluble Tripodal Imidazolyl Ligand as a Model for the Tris(histidine) Motif of Zinc Enzymes: Nickel, Cobalt and Zinc Complexes and a Comparison with Metal Binding in Carbonic Anhydrase
Authors: Kunz Peter C. , Reiß Guido J. , Frank Walter , Kläui Wolfgang
Published: October 2003

Tris[2‐isopropylimidazol‐4(5)‐yl]phosphane (4‐TIPiPr), a novel model ligand for the tris(histidine) motif of many zinc enzymes, has been prepared. 4‐TIPiPr is hydrolytically stable and soluble in protic solvents. It readily forms chloro‐ and nitratocobalt, ‐nickel and ‐zinc complexes in aqueous methanol. The crystal structures of the solvates [(4‐TIPiPr)Co(MeOH)(NO3)]NO3·2Et2O (3·2Et2O), [(4‐TIPiPr)Ni(MeOH)(NO3)]NO3·Et2O·MeOH (4·Et2O·MeOH), [(4‐TIPiPr)CoCl]Cl·MeOH·2.5H2O (5·MeOH·2.5H2O), and [(4‐TIPiPr)ZnCl]Cl·MeOH·2.5H2O (6·MeOH·2.5H2O) have been determined. The complex 3 shows striking structural similarities to the hydrogencarbonate complex of cobalt‐substituted human carbonic anhydrase II (HCA II). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis of New PdII Complexes Containing a Thioether‐Pyrazole Hemilabile Ligand − Structural Analysis by 1H, 13C NMR Spectroscopy and Crystal Structure of [PdCl(bdtp)]BF4 [bdtp = 1,5‐Bis(3,5‐dimethyl‐1‐pyrazolyl)‐3‐thiapentane]
Authors: García‐Antón Jordi , Pons Josefina , Solans Xavier , Font‐Bardia Mercè , Ros Josep
Published: October 2003

Treatment of the ligand 1,5‐bis(3,5‐dimethyl‐1‐pyrazolyl)‐3‐thiapentane (bdtp) with [PdCl2(CH3CN)2] led to a [PdCl2(bdtp)] complex. Subsequent treatment of this complex with AgBF4 gave [PdCl(bdtp)](BF4). These PdII complexes were characterised by elemental analysis, conductivity measurements, IR spectroscopy, and 1H and 13C NMR spectroscopy. Complex [PdCl2(bdtp)] was again obtained when the complex [PdCl(bdtp)](BF4) was heated under reflux in a solution of NEt4Cl in CH2Cl2/MeOH (1:1). Ligand bdtp in complexes 1 and 2 exhibited a hemilabile character. The X‐ray structure of the complex [PdCl(bdtp)](BF4) was determined. The metal atom is tricoordinated by the two azine nitrogen atoms and one thioether sulfur atom of the thioether‐pyrazole ligand, its coordination (distorted square planar) being completed with one chloride ion. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Binuclear Hydridoplatinum(II): One‐Pot Synthesis, INS Spectra and X‐ray Crystal Structure of [Pt2(dcype)2(H)3][BPh4] {dcype = 1,2‐Bis(dicyclohexylphosphanyl)ethane}
Authors: Bandini Anna Laura , Banditelli Guido , Manassero Mario , Albinati Alberto , Colognesi Daniele , Eckert Juergen
Published: October 2003

The binuclear platinum(II) hydride [Pt2(dcype)2(H)3][Cl] (1b) has been isolated in high yields by treatment of Pt(dcype)Cl2 with NaBH4 (molar ratio 1:2) in ethanol solution at room temperature. This one‐pot synthesis is not straightforward when starting from diphenylphosphanylalkane complexes. The compounds [Pt2(dppp)2(H)3][OH] (3b) and [Pt2(dppb)2(H)3][OH] (4) were isolated by starting from the mononuclear hydrides {cis‐[Pt(P‐P)(H)2]} while mixtures of both binuclear {[Pt2(dppe)2(H)3]+, 5} and trinuclear {[Pt3(dppe)3(H)3]+, 6} trihydrides were obtained with the dppe ligand. Various salts of the cation 1, [Pt2(dcype)2(H)3][X] (X = BF4, 1a; OH, 1c; BPh4, 1d), were isolated either from [Pt(dcype)(μ‐OH)]2[BF4]2 (2) by a general procedure (1a), or by decomposition of the complex cis‐[Pt(dcype)(H)2] in solution (1c), as well as by metathesis reactions (1a, 1c, and 1d). Compounds 1a, 1b, and 1d react with CO under mild conditions to afford the corresponding PtI binuclear hydrides [Pt2(dcype)2(μ‐CO)(μ‐H)][X] (X = Cl, 7a; BF4, 7b; BPh4, 7c). The binuclear core of cation 1 is broken by KCN in methanol solution, yielding the mononuclear complex cis‐[Pt(dcype)(CN)(H)] (8). The complexes 1a−d, 2, 7a−c, and 8 have been characterised by FAB MS, IR, and NMR (1H, 31P, and 195Pt) spectroscopic techniques; the 1 and 7 cations show fluxional behaviour on the NMR timescale. The structure of compound 1d was determined, at 200 K, by single‐crystal X‐ray diffraction. All the hydrido ligands were located. The Pt−Pt separation is 2.696(1) Å and the coordination geometry around each platinum centre can be regarded as distorted square planar. Incoherent Inelastic Neutron Scattering (INS) spectra were obtained for 1a and [Pt2(dppe)2(H)3][BF4] (5a); the spectra reflect the different geometries of the two “P4Pt2(H)3” cores as found by single‐crystal structure determinations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Crystal Structure, and Optical Properties of a New Molecular Complex of C60 with a Covalently Linked (FeIIITPP)2O Dimer
Authors: Litvinov Aleksey L. , Konarev Dmitri V. , Kovalevsky Andrey Yu. , Lapshin Alexander N. , Yudanova Evgeniya I. , Drichko Natalia V. , Coppens Philip , Lyubovskaya Rimma N.
Published: October 2003

A new molecular complex of C60 with covalently linked μ‐oxo dimer (FeIIITPP)2O are (TPP = tetraphenylporphyrin) was obtained. The complex has a neutral ground state and is formed mainly by van der Waals forces. The X‐ray analysis of the crystal structure of the complex showed it to have isolated packing of fullerenes in which each fullerene molecule is embraced in a pocket built by porphyrins. Optical properties and EPR behavior of the complex are described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Stepwise Assembly of Mixed Metal Dinuclear Carbonyl Complexes
Authors: Heinze Katja , Jacob Volker
Published: October 2003

The one‐pot/three‐step solution synthesis of a library of nine directional, dinuclear mixed‐metal complexes composed of different metal‐carbonyl units (M = Cr, Mo, W) and a bifunctional bridging isocyanide Schiff‐base ligand is described. The well‐defined metal sequence in these complexes with Cr, Mo, and W in two positions can be determined post‐synthesis by a combination of spectroscopic methods. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Group 10 Metal Complexes of SPS‐Based Pincer Ligands: Syntheses, X‐ray Structures, and DFT Calculations
Authors: Doux Marjolaine , Mézailles Nicolas , Ricard Louis , Le Floch Pascal
Published: October 2003

The 2,6‐bis(diphenylphosphanylsulfide)phosphinine (1) reacts with water to afford a 1,2‐dihydrophosphinine oxide 5 featuring a P−H bond. Reaction of 5 with one equivalent of [Pd(COD)Cl2] yields the SPS pincer‐based complex 6 with a P(OH) λ5‐phosphinine central ligand. Complex 6 has been structurally characterized. Two possible mechanisms account for the formation of 5: an intramolecular P−H to P−Pd metathesis or one based on the P=O to POH equilibrium. Methanol, ethanol or diethylamine also react with 1 to afford the corresponding P(H)(OMe) 7, P(H)(OEt) 8, and P(H)(NEt2) 9 λ5‐phosphinines. No definitive mechanism for the formation of 7−9 can be proposed since no intermediates were detected in situ by 31P NMR spectroscopy. However, DFT calculations (at the B3LYP 6‐311+G(d,p) level of theory) suggest that the conversion of 1,2‐dihydrophosphinines into λ5‐phosphinines is not viable because it involves a high activation energy. Like 5, λ5‐phosphinines 7 and 8 react with [Pd(COD)Cl2] to afford the expected palladium complexes 10 and 11. An alternative method relies on the reactivity of nucleophiles with a SPS pincer‐based complex 2 featuring a P−Cl bond. (−)‐Menthol and lithium diethylamide react with 2 to yield the expected P‐OMen 13 and P‐NEt2 14 complexes. Both complexes have been structurally characterized. Bromonickel 18 and chloroplatinum 19 complexes of the SPS ligand, featuring a P−Br or P−Cl bond, have also been prepared by reacting 1 with [NiBr2(DME)] and [Pt(COD)Cl2], respectively. Like their palladium congener, both species react with ethanol to afford the corresponding P−OEt derivatives 20 [M = Ni] and 21 [M = Pt]. nButyl derivatives of these SPS ligands also bind to Ni−Br (complex 22) and Pt−Cl (complex 23) fragments. Both complexes were straightforwardly prepared by reacting anion 3, resulting from the reaction of nBuLi with 1, with the [NiBr2(DME)] and [Pt(COD)Cl2] precursors. The chloride ligand is readily substituted by acetonitrile in complexes 4, 11, 20, and 21 upon treatment with AgBF4 in dichloromethane. Reaction of AgOTf with the palladium complex 4 affords complex 28 via substitution of the chloride ligand by TfO−. The X‐ray crystal structures of the dimethyl‐λ5 derivative 29 of 1, and that of its P‐OMe anion 30, have been recorded. Anion 30 can be regarded as a phosphanyl‐substituted pentadienyl anion. DFT calculations and a charge decomposition analysis (CDA) show that the phosphorus atom in these SPS‐pincer structures is a classical tertiary phosphane ligand in terms of donation and acceptance. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Lithium [Bis{benzoyl‐W(CO)5}(μ2‐hydrogen)] − A Charge‐Assisted H+‐Bridged Organometallic Complex Prepared by Selective Li+ Ion Replacement
Authors: Esterhuysen Matthias W. , Raubenheimer Helgard G.
Published: October 2003

Efficient syntheses and isolation procedures of two closely related benzoyl−W(CO)5 compounds, [{Li(diglyme)}{Ph(O)CW(CO)5}] (1) and [Li(diglyme)2][(μ2‐H){Ph(O)CW(CO)5}2] (2) are reported. The empirical formulae of 1 and 2 differ only in that the latter contains half the number of Li+ ions, with the balance of cations replaced by protons through an acidic silica gel filtration procedure. X‐ray structural investigations of both compounds revealed a self‐assembled polymeric Li+‐bridged structure for 1, and a strikingly dissimilar H+‐bridged structure for 2, thereby emphasising the important influences of strong, charge‐assisted hydrogen bonds on solid‐state structures. Possible implications of this novel route to charge‐assisted hydrogen bonds for crystal engineering are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture: Lithium [Bis{benzoyl‐W(CO)5}(μ2‐hydrogen)] − A Charge‐Assisted H+‐Bridged Organometallic Complex Prepared by Selective Li+ Ion Replacement (Eur. J. Inorg. Chem. 21/2003)
Authors: Esterhuysen Matthias W. , Raubenheimer Helgard G.
Published: October 2003

The cover picture shows the crystal structure of lithium bis[benzoyl‐W(CO)5][μ2‐hydrogen] (orange: tungsten; red: oxygen; blue: lithium; grey: carbon), a new class of hydrogen‐bridged organometallic complexes exhibiting strong, charge assisted hydrogen bonds between anionic metal−acyl moieties in Fischer‐type carbene precursors. The novel cation‐exchange procedure used here could find application in future organometallic crystal engineering studies involving carbonylmetal fragments. Details are discussed in the article by H. G. Raubenheimer et al. on p. 3861 ff. Dedicated to E. O. Fischer on the occasion of his 85th birthday
Regioselective Reduction of 2‐(Arylideneamino)isoindole‐1,3‐diones − Synthesis of Alkaloid Analogues by N‐Acylhydrazonium Ion Aromatic π‐Cyclization
Authors: Fogain‐Ninkam Alain , Daïch Adam , Decroix Bernard , Netchitaïlo Pierre
Published: October 2003

Hydroxylactams 6a−c and 7a−c were synthesized by successive regioselective reductions of arylideneaminophthalimides 3a−c, which were easily available from aminophthalimide 1 and benzaldehyde (2a) or thiophenecarboxaldehydes 2b and 2c. N‐Acylhydrazonium ions III, generated in the presence of Lewis acid from acetoxy derivatives 8a and 9a of hydroxylactams 6a and 7a, or in organic acid medium directly from hydroxylactams 6b and 6c, induced the expected isoindolo‐phthalazines 10a and 11a and thienopyridazino‐isoindolones 12b and 12c. On the other hand, hydroxylactams 7b and 7c under acidic conditions gave the unexpected N‐thienylmethyl‐substituted thienopyridazino‐isoindolones 13b and 13c. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Star‐Shaped Compounds Having 1,3,5‐Triazine Cores
Authors: Meier Herbert , Holst Hans Christof , Oehlhof Annette
Published: October 2003

The 1,3,5‐triazine derivatives 1−4 having styryl or higher oligo(phenylenevinylene) chains in the 2‐, 4‐, and 6‐positions represent star‐shaped push‐pull compounds. Alkoxy or dimethylamino groups on the peripheral benzene rings, which act as electron donors, and the central 1,3,5‐triazine ring, which acts as an electron acceptor, cause intramolecular charge transfer (ICT) to occur in the absorption S0⇄S1. Protonation of the 1,3,5‐triazine core enhances the effect, as demonstrated by a bathochromic shift; a secondary protonation on the dimethylamino groups, however, leads to the breakdown of the ICT. Thus, the yellow compound 1d first becomes violet and then colorless upon the addition of trifluoroacetic acid. In neutral solution, the long‐wavelength absorption of the series 1f, 2b, 3, and 4 converges to λ∞ = 427 nm (with an effective conjugation length nECL = 7). The absorption of the corresponding protonated compounds approaches λ∞ = 515 nm (nECL = 6). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Thermal Rearrangement of 1,5,8‐Triphosphaisolumibullvalenes (1,5,8‐Triphosphatetracyclo[4.4.0.02,8.05,7]deca‐3,9‐dienes)
Authors: Disteldorf Hendrik , Renner Jens , Heydt Heinrich , Binger Paul , Regitz Manfred
Published: October 2003

1,5,8‐Triphosphaisolumibullvalenes (1,5,8‐triphosphatetracyclo[4.4.0.02,8.05,7]deca‐3,9‐dienes) 3, when suitably substituted, undergo thermal rearrangement to afford the 1,1b,2a‐triphosphahomoquadricyclanes (tetrahydro‐1H‐1,1b,2a‐triphosphadicyclopropa[cd,gh]‐pentalenes) 6. The structure of the rearranged compound 6d was elucidated by X‐ray crystallography. The newly synthesized compound 6a undergoes addition of oxygen or sulfur with an increase in the coordination at the phosphorus atom P‐1 to yield the products 10a/b; it also undergoes complexation with Co2(CO)8 at the newly formed P−C≡C− unit to afford product 11. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A REKS Assessment of the Face‐Diagonal Bond in 1,3‐Didehydrocubane and a Comparison with Benzyne Biradicals
Authors: de Visser Sam P. , Filatov Michael , Schreiner Peter R. , Shaik Sason
Published: October 2003

The three isomeric cubane biradicals were studied using spin‐restricted ensemble‐referenced Kohn−Sham (REKS) density functional calculations at the B3LYP/6‐31G(d) level of theory. The most stable biradical was found to be ortho‐cubene with the meta‐cubene and para‐cubene biradicals 4.7 kcal mol−1 and 17.8 kcal mol−1 higher in energy, respectively. The singlet ground states are well separated from their lowest lying triplet states. These singlet‐triplet energy differences mostly originate from through‐space interactions for the ortho and meta isomers, whereas these interactions are rather weak for the para isomer. In contrast to para‐benzyne, which was also considered for comparison with an unsaturated system, the singlet‐triplet energy gap remains large in para‐cubadiyl, mainly as a result of its much stronger through‐bond interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
N‐(Arylsulfonyl)trihaloacetimidoyl Chlorides and Their Reactions with Phosphites
Authors: Rassukana Yuliya V. , Onys’ko Petro P. , Grechukha Anatolii G. , Sinitsa Anatolii D.
Published: October 2003

We have developed a convenient synthetic approach to highly reactive N‐(arylsulfonyl)trichloro‐ and ‐trifluoroacetimidoyl chlorides 2 by reacting the corresponding N‐acylsulfonamides with PCl5. The interaction of the imidoyl chlorides with phosphites proceeds through different pathways depending on the substituents in the reagents, and leads to N‐arylsulfonyl‐N‐trichlorovinylphosphoramidates 4, 1‐arylsulfonylamino‐1‐chlorotrifluoroethylphosphonate 5, C,N‐bis(phosphorylated) N‐dihalovinylsulfonamides 8 and α‐(arylsulfonylamino)trifluoroethylidenebis(phosphonates) 10. A rare example of an aza‐Perkow reaction involving a trifluoromethyl group was discovered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Novel DNA‐Damaging Tropolone Derivatives from Goupia glabra
Authors: Mesa‐Siverio Dulce , Estévez‐Braun Ana , Ravelo Ángel G. , Murguia Jose R. , Rodríguez‐Afonso Abigail
Published: October 2003

Two novel tropolone derivatives 1 and 2 have been isolated from Goupia glabra. Their structures were determined by extensive 1D and 2D NMR spectroscopic studies. Compound 2 constitutes the first example isolated from a natural source of a Diels−Alder adduct between a tropolone and a naphthalene derivative. Compounds 1 and 2 exhibit significant toxicity towards a panel of DNA damage checkpoint defective yeast mutants, and behave as genotoxins, which highlights their potential to be used as anticancer drugs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Proximate, “Parallel‐In‐Plane” Preoriented Bis(diazenes) − In‐Plane Delocalized Bis(homoconjugated) 4N/5(6)e Anions
Authors: Beckmann Eberhard , Bahr Nicolaus , Cullmann Oliver , Yang Fushun , Kegel Markus , Vögtle Markus , Exner Kai , Keller Manfred , Knothe Lothar , Prinzbach Horst
Published: October 2003

Synthetic details are presented for a series of more or less rigid, “parallel‐in‐plane” preoriented bis(diazenes), with N=N/N=N distances (d) of 3.3−2.9 Å and interorbital angles (ψ) of 142−164° (X‐ray crystal structures). DFT calculations (B3LYP/6−31G*) and one‐/two‐electron reduction experiments with the two least preoriented, most “distant” bis(diazenes) (dN=N/N=Nca. 3.3 Å; ψ 142−146°) provide more insight into the structural prerequisites for bis(homoconjugative) in‐plane electron delocalization in 4N/5e radical anions and 4N/6e dianions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
2,3‐Diferrocenylcyclopropenone: Synthesis, Structure, and Some Chemical and Electrochemical Properties
Authors: Klimova Elena I. , Klimova Berestneva Tatiana , Ramirez Lena Ruiz , Cinquantini Arnaldo , Corsini Maddalena , Zanello Piero , Hernández‐Ortega Simón , García Marcos Martínez
Published: October 2003

Alkylation of ferrocene with tetrachlorocyclopropene in the presence of AlCl3 followed by aqueous workup affords 2,3‐diferrocenylcyclopropenone in high yield. We have studied some of this ketone’s chemical transformations and electrochemical properties. 2,3‐Diferrocenylcyclopropenone withstands thermolysis; it is stable in an acidic medium; the action of tetrafluoroboric acid−diethyl ether results in the formation of diferrocenyl(hydroxy)cyclopropenylium tetrafluoroborate; nucleophiles, including methyllithium and lithium aluminum hydride, react regioselectively with the three‐membered ring by opening it to form the respective substituted cis‐diferrocenylethenes. We present data from X‐ray diffraction analyses of 2,3‐diferrocenylcyclopropenone, isopropyl cis‐2,3‐diferrocenylacrylate, and cis‐3,4‐diferrocenyl‐2‐methylbut‐3‐en‐2‐ol. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Protection of Hydroxy Groups with Diphenylmethyl and 9‐Fluorenyl Trichloroacetimidates − Effect on Anomeric Stereocontrol
Authors: Ali Ibrahim A. I. , Ashry El Sayed H. El , Schmidt Richard R.
Published: October 2003

The use of O‐diphenylmethyl (DPM) and the O‐(9‐fluorenyl) (Fl) trichloroacetimidates permitted efficient protection of alcohols. The compatibility of these groups with other chemical manipulations is demonstrated. Glucosylation of typical acceptors with an O‐glucopyranosyl trichloroacetimidate as donor having a DPM group at 2‐O afforded β‐glucopyranosides, thus demonstrating anchimeric assistance of the DPM group in the anomeric stereocontrol. This effect was also observed in mannopyranoside synthesis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Chemical Reactivity of α‐Oxo Aldehyde‐Supported Silicas
Authors: Kar Samiran , Joly Pascal , Granier Michel , Melnyk Oleg , Durand Jean‐Olivier
Published: October 2003

The synthesis and characterisation of α‐oxo aldehyde‐supported silicas by the sol‐gel procedure is described. The glyoxylyl group was generated after gelation, either by periodic oxidation of gluconamide chains or by deprotection of a diisopropylthioacetal‐protected derivative. The accessibility and reactivity of the supported α‐oxo aldehyde function was investigated in model reactions with hydroxylamine and hydrazine derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Formation, Isolation, and Spectroscopic Properties of Some Isomers of C60H38, C60H40, C60H42, and C60H44 − Analysis of the Effect of the Different Shapes of Various Helium‐Containing Hydrogenated Fullerenes on Their 3He Chemical Shifts
Authors: Peera Asghar , Saini Rajesh K. , Alemany Lawrence B. , Billups W. Edward , Saunders Martin , Khong Anthony , Syamala M. S. , Cross R. James
Published: October 2003

A complex mixture of C60H38 to C60H44 has been prepared by a much milder procedure (Benkeser reduction) than the hydrogenation procedures that have frequently been used to produce such highly hydrogenated derivatives of C60. 1H and 13C NMR spectra of fractions isolated by HPLC showed that more highly hydrogenated fullerenes exhibited signals that were shifted upfield. The opposite trend appears to hold in 3He NMR spectra of the corresponding endohedral helium compounds. The changes in the 1H, 13C, and 3He chemical shifts are reasonable for fullerenes hydrogenated to different extents. In particular, previously reported substantial changes in the shapes of the various hydrogenated fullerenes can reasonably account for the interesting trends apparent both in the 3He chemical shifts of He@C60Hx (x = 0−44) and in the HPLC retention times of the corresponding non‐helium‐containing species. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)