bluuebunny/crossref_metadata_2025 huggingface dataset:
Germ‐line transmission of a myocardium‐specific GFP transgene reveals critical regulatory elements in the cardiac myosin light chain 2 promoter of zebrafish
Authors: Huang Chiu‐Ju , Tu Chi‐Tang , Hsiao Chung‐Der , Hsieh Fong‐Jou , Tsai Huai‐Jen
Published: August 2003

In response to the lack of a transgenic line of zebrafish labeled with heart‐specific fluorescence in vivo to serve as a research model, we cloned a 1.6‐kb polymerase chain reaction (PCR) ‐product containing the upstream sequence (−870 bp), exon 1 (39 bp), intron 1 (682 bp), and exon 2 (69 bp) of the zebrafish cardiac myosin light chain 2 gene, (cmlc2). A germ‐line transmitted zebrafish possessing a green fluorescent heart was generated by injecting this PCR product fused with the green fluorescent protein (GFP) gene with ends consisting of inverted terminal repeats of an adeno‐associated virus. Green fluorescence was intensively and specifically expressed in the myocardial cells located both around the heart chambers and the atrioventricular canal. Neither the epicardium nor the endocardium showed fluorescent signals. The GFP expression in the transgenic line faithfully recapitulated with the spatial and temporal expression of the endogenous cmlc2. Promoter analysis showed that the fragment consisting of nucleotides from −210 to 34 (−210/34) was sufficient to drive heart‐specific expression, with a −210/−73 motif as a basal promoter and a −210/−174 motif as an element involved in suppressing ectopic (nonheart) expression. Interestingly, a germ‐line of zebrafish whose GFP appeared ectopically in all muscle types (heart, skeletal, and smooth) was generated by injecting the fragment including a single nucleotide mutation from G to A at −119, evidence that A at −119 combined with neighboring nucleotides to create a consensus sequence for binding myocyte‐specific enhancer factor‐2. Developmental Dynamics 228:30–40, 2003. © 2003 Wiley‐Liss, Inc.
Novel regulatory sequence −82/−62 functions as a key element to drive the somite‐specificity of zebrafish myf‐5
Authors: Chen Yau‐Hung , Lee Hung‐Chieh , Liu Chia‐Feng , Lin Cheng‐Yung , Tsai Huai‐Jen
Published: August 2003

Myf‐5, a transcription factor that controls muscle differentiation, is expressed in somites during early embryogenesis. However, gene regulation of myf‐5 is poorly understood and detailed functional analysis of the regulatory cis‐elements is needed. In zebrafish, the myf‐5 upstream sequence from −82 to −62 (−82/−62) was fused with a basal promoter and transferred to fertilized zebrafish eggs. The −82/−62 cassette drove green fluorescent protein (GFP) reporter gene expression specifically in the somites. Moreover, GFP signals were detected exclusively in the somites of 28‐hpf embryos derived from eggs injected with pCMV‐5×(−82/−62), which contained five copies of the −82/−62 cassette inserted within cytomegalovirus promoter/enhancer. Thus, the −82/−62 cassette, conserved in mouse myf‐5, functions to drive somite‐specific expression and to repress nonspecific expression during the early development of zebrafish embryos. Mutated sequence analysis of −82/−62 cassette showed that the −70/−62 sequence was the key element for controlling myf‐5 specificity. The putative CCAAT‐like box, located at −66/−62, could not direct somite‐specific expression. A DNA‐protein complex was specifically formed between the −70/−62 probe and embryonic nuclear extracts. We conclude that the −70/−62 motif is essential for controlling somite‐specific expression and the CCAAT‐like box is essential for activating gene transcription. Developmental Dynamics 228:41–50, 2003. © 2003 Wiley‐Liss, Inc.
Ece1 and Tbx1 define distinct pathways to aortic arch morphogenesis
Authors: Morishima Masae , Yanagisawa Hiromi , Yanagisawa Masashi , Baldini Antonio
Published: August 2003

Pharyngeal arch artery (PAA) remodeling defects account for several cases of congenital heart disease. Mutations in the Endothelin‐1 genetic pathway or Tbx1, a candidate
gene for DiGeorge syndrome, cause similar aortic arch defects. Previous research suggests that Tbx1 may trigger diffusible signals from the pharyngeal arches to support the growth of the PAAs that
contribute to the mature aortic arch. The demonstration of genetic interaction between Tbx1 and Fgf8 pointed to FGF signaling as a possible candidate. Because Fgf8 interacts with
Endothelin‐1 signaling and because Endothelin‐1 signaling interacts with neural crest‐derived cells in the pharyngeal apparatus, we hypothesized that Tbx1 and
Endothelin‐1 signaling may contribute to the same pathway required for aortic arch morphogenesis. Therefore, we have analyzed mice mutated for the endothelin converting enzyme
(Ece1) or Tbx1 genes and compound mutants. Results show that the two genes have different roles in the remodeling of the PAAs and do not interact. We propose that Tbx1
is required for the formation and early growth and remodeling of the PAAs, whereas Ece1 is necessary for regression of the cranial arch arteries and growth of the most caudal arch arteries. The
latter function is likely related to the known role of the Endothelin‐1 pathway in neural crest function. Developmental Dynamics 228:95–104, 2003. © 2003 Wiley‐Liss, Inc.
Expression of NG2 proteoglycan during endochondral and intramembranous ossification
Authors: Fukushi Jun‐ichi , Inatani Masaru , Yamaguchi Yu , Stallcup William B.
Published: August 2003

We have used immunohistochemistry to study the distribution of the NG2 proteoglycan during bone development in the mouse. At embryonic day 15.5, NG2 was strongly detected in the immature cartilage of developing limbs. After transient down‐regulation in mature chondrocytes, NG2 was up‐regulated during primary ossification, colocalizing with alkaline phosphatase and tenascin C. In the epiphyseal growth plates of newborn mouse tibia, NG2 and alkaline phosphatase exhibited overlapping patterns of expression by hypertrophic chondrocytes and by osteoblasts surrounding newly formed bone trabeculae. NG2 was down‐regulated after puberty, being only faintly detectable in the tibial growth plates of 3‐month‐old mice. In cranial sutures, NG2 was strongly labeled in osteogenic bone fronts and in the suture matrix. Our results indicate that NG2 expression is up‐regulated during both endochondral and intramembranous ossification, but is down‐regulated as ossification is completed. Developmental Dynamics 228:143–148, 2003. © 2003 Wiley‐Liss, Inc.
Epidemiology and risk factors of eating disorders: A two‐stage epidemiologic study in a Spanish population aged 12–18 years
Authors: Rojo Luis , Livianos Lorenzo , Conesa Llanos , García Angeles , Domínguez Alberto , Rodrigo Gloria , Sanjuán Lluis , Vila Marisa
Published: August 2003

Objective

The authors studied the prevalence rates of eating disorders (ED) and their risk factors in a Spanish population aged 12–18 years.

Method

A two‐stage epidemiologic study was conducted in the province of Valencia. Educational centers, classrooms, and individuals were selected randomly. The initial sample comprised 544 subjects. During Stage 1, subjects were screened with the 40‐item Eating Attitude Test and a sociodemographic questionnaire that evaluates risk factors. During Stage 2, a semistandardized clinical interview was conducted with each participant. A random control group was paired by class, age, and sex. Comorbid psychiatric disorders and partial and subclinical forms were detected using criteria in the 4th ed. of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV).

Results

Using DSM‐IV criteria, the morbidity rate was 2.91%, women comprised 5.17% of the sample, men comprised 0.77% of the sample, and the sex ratio was 6.71. Using DSM‐IV criteria, including subclinical forms, the morbidity rate was 5.56%, women comprised 10.3% of the sample, men comprised 1.07% of the sample, and the sex ratio was 9.63. Six risk factors were isolated: psychiatric comorbidity, friend on a diet in the last year, desire to lose weight, desire to be less corpulent, sentimental problems, and diet in the last year.

Discussion

This is the first Spanish two‐stage epidemiologic study to include a control group and to investigate risk factors. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 34: 281–291, 2003.
Ecologic momentary assessment of eating‐disordered behaviors
Authors: Stein Karen Farchaus , Corte Colleen M.
Published: August 2003

Objective

This pilot study evaluated the feasibility of ecologic momentary assessment (EMA) to measure five eating disorder behaviors and to examine reactivity of these behaviors to this measurement approach. The pattern of correspondence between EMA and the Eating Disorder Examination (EDE) was also examined.

Methods

Women with threshold or subthreshold anorexia and bulimia nervosa (N= 16) recorded their eating disorder behaviors for 4 weeks on a hand‐held computer. Upon completion of the EMA procedure, the EDE was administered.

Results

Eighty‐eight percent of the sample completed the EMA behavioral recording. No differences in behavioral frequency were found in the first and second halves of the EMA measurement period, suggesting that behaviors were not reactive to the methodology. Binging and excessive exercise were lower when measured by EMA compared with the EDE.

Discussion

These results suggest that EMA is a feasible and valid approach to the measurement of disordered eating behaviors. © 2003 by Wiley Periodicals, Inc. Int J Eat Disord 34: 349–360, 2003.
Synthesis, Properties, and Reactions of Trinuclear Macrocyclic Nickel(II) and Nickel(I) Complexes: Electrocatalytic Reduction of CO2 by Nickel(II) Complex
Authors: Lee Eun Young , Hong Daewon , Park Han Woong , Suh Myunghyun Paik
Published: August 2003

The trinuclear NiII complex of trismacrocyclic ligand 1, [Ni3(1)](ClO4)6, where 1 is 8,8′,8"‐(2,2′,2"‐nitrilotriethyl)tris(1,3,6,8,10,13,15‐heptaazatricyclo[11.3.1.13,15]octadecane), has been synthesized by template condensation reactions and shown to have poor axial binding ability. Cyclic voltammetry of the complex shows a three‐electron reversible reduction at −1.59 V and an irreversible oxidation at +1.25 V vs. Ag/Ag+ (0.01 M). Differential pulse voltammetry and Osteryoung square‐wave voltammetry indicate that the three NiII ions are electrochemically independent. A single crystal was obtained as [Ni3(1)](ClO4)3·Cl3·10H2O and its X‐ray structure was determined. When [Ni3(1)](ClO4)6 was reduced to a NiI species by reaction with Na(Hg) in MeCN, [Ni3(1)](ClO4)3 was isolated. [Ni3(1)](ClO4)6 shows catalytic activity for the electrochemical reduction of CO2 to CO in MeCN/H2O (9:1, v/v), as revealed by cyclic voltammetry and controlled‐potential coulometry. The catalytic efficiency of [Ni3(1)]6+ is lower than that of [Ni(cyclam)]2+. It gives a greater ip(CO2)/ip(N2) value but produces less CO per nickel center (3: 8‐methyl‐1,3,6,8,10,13,15‐heptaaza‐tricyclo[11.3.1.13,15]octadecane) compared with monometallic [Ni(3)]2+. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Heteronuclear Metal−Metal Contacts between Gold(I) and Group‐11, ‐12, and ‐13 Centers
Authors: Bardajía Manuel , Laguna Antonio
Published: August 2003

Closed‐shell interactions occur mainly for some heavy late transition metals and main‐group elements. In fact, these are dispersion forces reinforced by relativistic effects and by ionic components, of which the former are maximized in heteronuclear interactions. Heteronuclear compounds containing gold(I) and group‐11, ‐12, and ‐13 metals display d10−d10 or d10−s2 closed‐shell interactions of intermediate strength relative to the homonuclear metal−metal interactions. The number of examples of gold(I)−gold(I) contacts is large, but representatives of heteronuclear gold(I)−metal contacts are still scarce. There are two general types of derivatives displaying short gold−metal distances: those with bridging ligands and those with unbridged ones, of which the latter are always the more indicative of the presence of a real bond. Derivatives featuring unsupported gold−metal bonds have been obtained mainly through reactions between basic gold(I) complexes and acid complexes, and also by encapsulation of metal centers in metallocryptands. Most derivatives with supported gold−metal bonds have been synthesized by use of C‐donor ligands or ambidentate ligands. The gold−metal contacts dramatically affect the conformations and the aggregation of the molecules, and also their optical properties. Some of these derivatives are, in fact, intensely luminescent. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Relativistic Density Functional Study of the Dinuclear Uranyl Complex [(UO2)2(μ2‐OH)2Cl2(H2O)4] in Its Crystalline Environment
Authors: Schlosser Florian , Krüger Sven , Rösch Notker
Published: August 2003

The hexavalent dinuclear uranyl dichloride complex [(UO2)2(μ2‐OH)2Cl2(H2O)4] was studied computationally with an all‐electron scalar relativistic density functional method. This suggested hydrolysis product of uranyl in the presence of chlorine ions is one of the few polynuclear uranyl species for which a crystal structure is known. The calculated gas‐phase structure is similar to the experimental crystal geometry; any major deviations are due to hydrogen bonds in the crystal. If the eight strongest hydrogen bonds are included in a model of the complex’s crystalline environment, the calculated structure improves significantly. Based on this model, the hydrogen bond lengths and angles were determined, indicating that they are moderate and strong with an average binding energy of 39 kJ/mol. These computational results corroborate earlier suggestions based on experimental results concerning the location and strength of the hydrogen bonds. In addition, a valuable reference for relativistic quantum chemical methods is provided by the gas‐phase results. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The First Structurally Characterized Aluminum Squaraine Complex: L2(AlMe2)4·2THF·2toluene [L = Bis(2,6‐diisopropylanilino)squaraine]
Authors: Rong Junfeng , Peng Ying , Roesky Herbert W. , Li Jiyang , Vidovic Denis , Magull Jörg
Published: August 2003

Bis(2,6‐diisopropylanilino)squaraine (1) was prepared by condensation of squaric acid and 2,6‐diisopropylaniline. Treatment of 1 with trimethylaluminum affords a novel dimeric aluminum squaraine complex: L2(AlMe2)4· 2THF·2toluene [L = bis(2,6‐diisopropylanilino)squaraine] (2), which was characterized by X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Metal Complexes of a Novel Achiral Symmetric Pentadentate Ligand − Crystal Structures of Monohelical Zinc(II) and Cadmium(II) Complexes
Authors: Pedrido Rosa , Bermejo Manuel R. , García‐Deibe Ana M. , González‐Noya Ana M. , Maneiro Marcelino , Vázquez Miguel
Published: August 2003

By both electrochemical synthesis and a traditional chemical procedure the interaction of the pentadentate ligand 2,6‐bis{1‐[2‐(tosylamino)phenylimino]ethyl}pyridine (H2DAPATs), with MnII, FeII, CoII, NiII, CuII, ZnII and CdII gives rise to neutral mononuclear complexes that have been characterised by elemental analyses, FAB mass spectrometry, IR, 1H and COSY NMR spectroscopy and magnetic measurements, where appropriate. Recrystallisation of the zinc complex obtained electrochemically yielded single crystals of [Zn(DAPATs)] (1), while recrystallisation of cadmium complexes obtained by both techniques afforded the same structure, [Cd(DAPATs)(H2O)] (2). Both 1 and 2 are monohelical single‐stranded compounds with different coordination geometries. In the zinc complex, the metal ion assumes a distorted trigonal‐bipyramidal geometry involving the N5 atoms of the dianionic ligand. For cadmium complexes the metal ion is in a distorted pentagonal‐pyramidal environment, as the result of coordination to the N5 ligand donor set and an additional water molecule. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Characterization and Electrochemical Properties of Optically Active [60]Fullerene Organotransition Metal Complexesmer‐[(η2‐C60)M(CO)3{(−)‐DIOP}] (M = Mo, W),mer‐[(η2‐C60)M(CO)3{(+)‐DIOP}] (M = Mo, W) and [(η2‐C60)M{(−)‐DIOP}] (M = Pd, Pt) − Crystal Structure of [(η2‐C60)Pt{(−)‐DIOP}]
Authors: Song Li‐Cheng , Liu Peng‐Chong , Liu Jin‐Ting , Su Fu‐Hai , Wang Guang‐Feng , Hu Qing‐Mei , Zanello Piero , Laschi Franco , Fontani Marco
Published: August 2003

This paper reports on several new optically active organometallic [60]fullerene complexes that contain a chiral (+)‐DIOP or (−)‐DIOP ligand [DIOP = 2,3‐O,O′‐isopropylidene‐2,3‐dihydroxy‐1,4‐bis(diphenylphosphanyl)butane]. The Mo/W complexesmer‐[(η2‐C60)M(CO)3{(−)‐DIOP}] (1, M = Mo;2, M = W) andmer‐[(η2‐C60)M(CO)3{(+)‐DIOP}] (3, M = Mo;4, M = W) were synthesized by a photochemical reaction of a mixture of [M(CO)6], (−)‐DIOP or (+)‐DIOP and C60in chlorobenzene in 42−51% yields, whereas the Pd/Pt complexes [(η2‐C60)M{(−)‐DIOP}] (5, M = Pd;6, M = Pt) were prepared by a thermal reaction of C60with [M(PPh3)4], followed by in situ treatment of the intermediate [(η2‐C60)M(PPh3)2] with (−)‐DIOP, in toluene in > 90% yields. All the new complexes1−6were fully characterized by elemental analysis,1H (31P,13C) NMR, IR, UV/Vis and circular dichroism (CD) spectroscopy. The structure of [(η2‐C60)Pt{(−)‐DIOP}] (6) was further confirmed by X‐ray diffraction techniques. The electrochemical properties of complexes1,2,5and6were studied in dichloromethane solution. Complexes1and2display the reversible, four‐membered, one‐electron reduction sequence typical of fullerene ligands, as well as the reversible (in the cyclic voltammetric time scale) one‐electron oxidation of the outer metal fragment. Complexes5and6are less stable to the same electron transfer processes. EPR measurements suggest that in the different electrogenerated monoanions, the added electrons enter the LUMO orbitals partially contributed by the metal fragment. In addition, they confirm that the instability of the reduction intermediates is due to the release of free C60. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Syntheses, Structures and Theoretical Investigations of 1λ4,3λ4,5λ4‐Trithia‐2,4,6,8,9‐pentaazabicyclo[3.3.1]nona‐1(9),2,3,5,7‐pentaenes
Authors: Knapp Carsten , Lork Enno , Borrmann Tobias , Stohrer Wolf‐Dieter , Mews Rüdiger
Published: August 2003

The syntheses of the title compounds RCN5S3 with electron‐withdrawing aryl substituents [R = 2‐FC6H4 (1m), 4‐FC6H4 (1n), 2,6‐F2C6H3 (1o), C6F5 (1p), 4‐NCC6H4 (1q) and Cl3C (1r)] are described. The X‐ray structures of 1n, 1o, 1q and 1r, together with those of Me2NCN5S3 (1b) and 4‐CH3C6H4CN5S3 (1f), are reported. The experimentally determined dependence of the bond lengths on the substituents R within the bicyclic system RCN5S3 is well‐reflected in the results of the theoretical calculations (RHF, MP2, B3LYP). The bonding model developed shows that acceptor substituents do not influence bonding within the bicycle. In the solid state, two fundamentally different primary interactions of the RCN5S3 molecules are observed; “stacking” and “dimerisation”, which can be rationalised by electrostatic interactions between the CN5S3 units. However, secondary effects − the interactions between the R substituents − may be even more dominant. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Palladium(II) Complexes Containing a Pyridinyliminophosphorane Ligand
Authors: Wu Hung‐Ren , Liu Yi‐Hung , Peng Shie‐Ming , Liu Shiuh‐Tzung
Published: August 2003

A series of new pyridinyliminophosphorane bidentate ligands with different steric environments [(2‐C6H4N)PPh2=NAr (NPN)] and their methylpalladium complexes [PdClMe(NPN)] were prepared. From the crystal structure analysis it is evident that the alkyl ligands are always trans to the pyridinyl nitrogen donor, revealing a σ‐donating ability of the iminophosphorane. However, the two Pd−Cl bonds in [PdCl2(NPN)] are essentially the same length. Cationic palladium complexes catalyzed the copolymerization of norbornene/ethylene as well as CO/norbornene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Geometrical and Linkage Isomers of [OsCl2(dmso)4] − The Complete Picture
Authors: Alessio Enzo , Serli Barbara , Zangrando Ennio , Calligaris Mario , Panina Natalia S.
Published: August 2003

The isomerisation between the three known isomers of the [OsCl2(dmso)4] complex — trans‐[OsCl2(dmso‐S)4] (1), cis,fac‐[OsCl2(dmso‐S)3(dmso‐O)] (2), and cis‐[OsCl2(dmso‐S)4] (3) — has been investigated by NMR spectroscopy, X‐ray crystallographic analysis, and DFT calculations. We show that the two dmso‐linkage isomers 2 and 3 equilibrate slowly at room temperature in solutions of both dimethyl sulfoxide (DMSO) and light‐protected chloroform. Although crystals of 2 precipitate from DMSO solutions, crystals of 3 were obtained from chloroform solutions. Compound 2 isomerises to 1 after exposure to sunlight, while 1 transforms into 2 in hot DMSO solution. The molecular energies were calculated by DFT methods, which show that in the gas phase there are small differences in the total energies (Et), with 1 exhibiting the lowest energy, in contrast with its low population in solution. This result indicates that the stability of each isomer in solution is not simply determined by Et, but that the solvent plays an important role. In fact, quantum chemical calculations for the isomerisation process 1 ⇄ 2 show a marked increase in the equilibrium constant with increasing the solvent polarity. The calculation of the metal−dmso binding energies, in combination with the X‐ray data, shows a significantly higher strength of Os−S bonds with respect to Ru−S bonds, which explains the different behaviour of otherwise analogous osmium−dmso and ruthenium−dmso complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
The Substitution Reaction of (Chloro)bis(tetraisopropylcyclopentadienyl) Complexes of La, Pr, or Nd with Silylamides
Authors: Schmitt Oliver , Wolmershäuser Gotthelf , Sitzmann Helmut
Published: August 2003

The dimeric complexes [{(C5HR4)2Ln(μ‐Cl)(μ3‐Cl)Na(OEt2)}2] (1) (R = CHMe2, Ln = La, Pr, Nd) eliminate sodium chloride in toluene solution to form the (chloro)bis(cyclopentadienyl) complexes [(C5HR4)2LnCl] (2). Crystalline 2‐Nd contains monomeric molecules exhibiting two intramolecular Nd···CH3 interactions (Nd···C = 3.32 Å) with ring substituents. Reaction of complexes 1 with bis(trimethylsilyl)amides furnishes the tetranuclear complexes [{(C5HR4)2Ln(μ‐Cl)}2{NaN(SiMe3)2}2] (3) (R = CHMe2, Ln = La, Pr, Nd), which have been characterized by X‐ray crystal structure analyses. In solution the La2Na2 complex 3‐La eliminates NaC5HR4 (R = CHMe2) to form a mixture of 2‐La and [(C5HR4)La{N(SiMe3)2}2] (4). With less a bulky bis(dimethylsilyl)amide 1‐La yields the substitution product [(C5HR4)2LaN(SiHMe2)2] (5) (R = CHMe2). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
(4‐Acyl‐5‐pyrazolonato)titanium Derivatives: Oligomerization, Hydrolysis, Voltammetry, and DFT Study
Authors: Caruso Francesco , Massa Lou , Gindulyte Asta , Pettinari Claudio , Marchetti Fabio , Pettinari Riccardo , Ricciutelli Massimo , Costamagna Juan , Canales Juan Carlos , Tanski Joseph , Rossi Miriam
Published: August 2003

Twenty 4‐acyl‐5‐pyrazolonato (Q) titanium derivatives of varied nuclearity have been synthesized from Ti(OR)4 or TiCl4 and characterized with spectroscopic methods (IR, NMR, ESI‐MS). While Ti−(β‐diketonato) cleavage is not seen in isolated solids, Ti−O(alkoxy) (or Ti−Cl) bonds cleave upon hydrolysis, leading to several structural forms, including oligomers. Ionic Q species with no Ti, i.e., obtained after Ti−Q cleavage, are seen for some Ti−Q derivatives by ESI‐MS, which also indicates a varied nuclearity for a given species, e.g., the isolated polynuclear [Q2Ti‐μ‐O]n has several “n” values. Mononuclear Ti complexes are obtained under rigorous anhydrous conditions. The cis structures of the mononuclear species (QT)2Ti(OCH3)2, QT = 3‐methyl‐4‐(neopentylcarbonyl)‐1‐phenylpyrazol‐5‐onato have been analyzed with DFT methods. A trans influence is a major driving force that accounts for several sets of Ti−O bonds. One of the cis stereoisomers is 56 kcal/mol higher in energy than the other two. In contrast, all (QT)2TiCl2 cis isomers show similar energies. Voltammetry of the mononuclear species (QT)2Ti(OnPr)2 and the antitumor tetranuclear compound [(QB)2Ti‐μ‐O]4, (QB = 4‐benzoyl‐3‐methyl‐1‐phenylpyrazol‐5‐onato) indicate that the TiIV is less prone to reduction to TiIII in the latter (Epc for the TiIV/TiIII couple is −1.71 V and −1.46 V versus Fc+/Fc, respectively). Potential antitumor compounds having a Ti/Q ratio of 1:1 do not disproportionate, unlike the equivalent acetylacetonato derivatives, and are water‐soluble. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Large‐Scale Synthesis of High Quality Trigonal Selenium Nanowires
Authors: An Changhua , Tang Kaibin , Liu Xianming , Qian Yitai
Published: August 2003

A direct and simple one‐step hydrothermal reaction route has been developed for the synthesis of high quality trigonal selenium (t‐Se) nanowires at 110 °C, with (NH4)2S2O3 and Na2SeO3 as starting materials in the presence of the surfactant sodium dodecyl sulfate (SDS). The diameter of the trigonal selenium nanowires can be tuned by carefully adjusting the initial feedstock concentration. The unusual chain like structure of the target material plays a key role in determining the final morphologies of the products. Several factors, such as initial concentration of the feedstock, the presence of surfactant, and the temperature which influences the quality of the t‐Se nanowires, have been investigated. The optical properties of the t‐Se nanowires with different diameters were examined by means of UV/Vis absorbance spectroscopy at room temperature. The investigation revealed that the absorbance peak for the t‐Se nanowires with diameters of 20−40 nm shifts to the blue, relative to those for bulk t‐Se nanowires (374 nm) and nanowires with diameters of 50−130 nm (306 nm). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Polynuclear Nickel(II) Complexes: Preparation and Magnetic Properties of NiII4, NiII5, and NiII6 Species with Ligands containing O∩X∩O (X = S, Se or N) Donor Atoms
Authors: Paine Tapan K. , Rentschler Eva , Weyhermüller Thomas , Chaudhuri Phalguni
Published: August 2003

A family of bisphenol‐containing ligands with XO2 donor atoms, where X = S, Se, or N, yields [NiII]4 (1) and (2), [NiII]5 (3), and [NiII]6 (4) complexes. Complex 2, 3, and 4 have been structurally characterised by X‐ray diffraction. The compounds were characterised spectroscopically and by variable‐temperature (2−295 K), variable‐field (1, 4, and 7 T) magnetic susceptibility measurements. Analysis of the magnetic data shows predominant ferromagnetic interactions between the nickel centres (SNi = 1) indicating “high‐spin” ground states for 1, 2, and 3, whereas complex 4 shows antiferromagnetic interactions. A plot of J vs. Ni−O−Ni angles for all structurally characterised Ni4O4 cubane cores, including 2, irrespective of their symmetry, shows a large variation of J values within a small range of Ni−O−Ni angles. A simple two‐J model was found to be adequate to describe the magnetic properties of the hexanuclear complex, 4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Mononuclear Rhodium(I) Complexes with Chelating N‐Heterocyclic Carbene Ligands − Catalytic Activity for Intramolecular Hydroamination
Authors: Burling Suzanne , Field Leslie D. , Li Hsiu L. , Messerle Barbara A. , Turner Peter
Published: August 2003

The mononuclear cationic RhI complexes [Rh(cod)(mdd)]+X− and [Rh(CO)2(mdd)]+X− (X = BPh4, PF6) containing the chelating bidentate N‐heterocyclic carbene ligand 1,1′‐methylene‐3,3′‐dimethyldiimidazoline‐2,2′‐diylidene (mdd) have been synthesised and spectroscopically characterised. The complexes [Rh(cod)(mdd)]+BPh4− and [Rh(CO)2(mdd)]+PF6− have also been characterised by X‐ray crystallography. The dicarbonyl complexes catalyse the intramolecular hydroamination of 4‐pentyn‐1‐amine to 2‐methyl‐1‐pyrroline. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Kinetic Study and Molecular Orbital Investigation of Cadmium(II), Mercury(II) and Lead(II) Complexes with the Mixed Pendant‐Arm Macrocyclic Ligand 1,7‐Bis(carboxymethyl)‐4,10‐bis(1‐methylimidazol‐2‐ylmethyl)‐1,4,7,10‐tetraazacyclododecane
Authors: Di Vaira Massimo , Mani Fabrizio , Costantini Stefano Seniori , Stoppioni Piero , Vacca Alberto
Published: August 2003

The neutral [ML6]·3H2O complexes (M = CdII, HgII and PbII) formed with the potentially octadentate ligand 1,7‐bis(carboxymethyl)‐4,10‐bis(1‐methylimidazol‐2‐ylmethyl)‐1,4,7,10‐tetraazacyclododecane (H2L6) in its anionic deprotonated form, which bears two pairs of different dangling groups in trans positions on the cyclen skeleton, have been synthesized. Their low‐temperature limiting NMR spectra (1H and 13C) in D2O show that both the dangling groups and the ethylenic moieties of the macrocycle ring are in a fixed conformation in all complexes at 273 K. These conditions are relaxed at higher temperatures, yielding a dynamic behaviour that proceeds through both ring inversion and rearrangement of the pendant arms. The kinetic parameters for ring inversion have been obtained from the temperature‐dependent 13C NMR spectra. Cd: k(298 K) = 236 s−1; ΔH‡ = 72.9 ± 0.6 kJ·mol−1; ΔS‡ = 45 ± 2 J K−1·mol−1; Hg: k(298 K) = 292 s−1; ΔH‡ = 68 ± 3 kJ·mol−1; ΔS‡ = 29 ± 10 J K−1·mol−1; Pb: k(298 K) = 122 s−1; ΔH‡ = 65 ± 2 kJ·mol−1; ΔS‡ = 14 ± 5 J K−1·mol−1. In the absence of experimental structure determinations, some insight into the geometries has been obtained by quantum‐mechanical calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A Bulky Chelating Diamidoaluminum Monohydride − Synthesis, Structure and Reactions with Me3SnF and Heavy Group 16 Elements
Authors: Zhu Hongping , Chai Jianfang , Roesky Herbert W. , Noltemeyer Mathias , Schmidt Hans‐Georg , Vidovic Denis , Magull Jörg
Published: August 2003

The bulky chelating diamidoaluminum monohydride [ArN(CH2)3NAr]AlH(NMe3) (Ar = 2,6‐iPr2C6H3; 1) was prepared in excellent yield from the reaction of the diamine ArNH(CH2)3HNAr with a small excess of AlH3·NMe3 in toluene. Subsequent fluorination of 1 with Me3SnF resulted in the formation of the aluminum monofluoride [ArN(CH2)3NAr]AlF(NMe3) (2). Reaction of 1 with elemental E (E = S, Se and Te) proceeded in toluene with heating to yield the aluminum chalcogenides {[ArNH(CH2)3NAr]Al(μ‐E)}2 [E = S (3), Se (4), and Te (5)]. The structures of complexes 1, 2 and 4 have been determined by X‐ray diffraction analyses. Compounds 1 and 2 are well‐separated monomers with a central aluminum atom in a tetrahedral environment. The diamide ligand [ArN(CH2)3NAr]2− chelates the Al atom to form a distorted six‐membered AlN2C3 ring which features a boat conformation for 1 and a flattened chair conformation for 2. Compound 4, however, is a dimer with a central Al2Se2 core bearing an ideal four‐membered planar ring and two six‐membered AlN2C3 rings, both displaying a boat conformation. The latter two rings are arranged perpendicularly to the Al2Se2 core in a trans configuration. The IR spectra and 1H NMR spectroscopic data of compounds 3−5 suggest that the migration of the hydrogen from selenium to one of the nitrogens at the diamide ligand is involved in the course of the reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Nanoparticulated Gold: Syntheses, Structures, Electronics, and Reactivities
Authors: Schmid Günter , Corain Benedetto
Published: August 2003

This microreview deals mainly with the synthesis and the electronic and chemical properties of gold nanoparticles. Modern synthetic routes, based on physical and on chemical procedures, as well as structural and optical features, are described. The bulk‐to‐molecule transition is discussed by studying size‐controlled quantum‐size effects, resulting in the determination of discrete electronic energy levels in Au55 clusters. Conductivity measurements of three‐ and two‐dimensionally organized ligand‐protected Au55 clusters are described, as well as the current techniques for the generation of ordered monolayers and artificial patterns of quantum dots. Finally, some aspects of the chemical activity of gold nanoparticles are discussed by considering ligand‐exchange processes and, last but not least, the expanding role of gold nanoparticles in catalysis is considered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structure and Reactivity of New Late Transition Metal Complexes Bearing Diphosphane Ligands Derived from Bis(pyrazol‐1‐yl)methane
Authors: Otero Antonio , Carrillo‐Hermosilla Fernando , Terreros Pilar , Expósito Teresa , Rojas Sergio , Fernández‐Baeza Juan , Antiñolo Antonio , López‐Solera Isabel
Published: August 2003

Modification of the multistep synthesis of the previously described bis[5‐(diphenylphosphanyl)pyrazol‐1‐yl)]methane (bppzm, 1) produces the novel diphosphane (diphenylphosphanyl)‐[5‐(diphenylphosphanyl)pyrazol‐1‐yl](pyrazol‐1‐yl)methane (p4m, 2). Treatment of this ligand with [MCl2(PhCN)2] (M = Pd, Pt) or [M(COD)(THF)2]BF4 (M = Rh, Ir) produces [MCl2(p4m)] (M = Pd 3, Pt 4) or [M(COD)(p4m)]BF4 (M = Rh 5, Ir 6) complexes, which chelate in a P,P‐bidentate fashion. Sulfidation of bppzm and p4m produces the disulfidophosphanes bppzmS2 (7) and p4mS2 (8). Treatment of 7 and 8 with [PdCl2(PhCN)2] produces [PdCl2(bppzmS2)] (9) and [PdCl2(pmS2)] (10), respectively, in which ligands 7 and 8 act in an N,N‐bidentate chelate fashion. In contrast, ligand 8 reacts with [Rh(COD)(THF)2]BF4 to produce [Rh(COD)(p4mS2)]BF4, where ligand 7 acts in a dynamic S,S‐chelate fashion. The activity of some of these complexes in the catalytic hydrogenation of olefins is reported and the single‐crystal X‐ray structures of 4, 8, and 9 have been obtained. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Partially Fluorinated Rare Earth Metal Complexes
Authors: Neculai Ana Mirela , Neculai Dante , Nikiforov Grigori B. , Roesky Herbert W. , Schlicker Christine , Herbst‐Irmer Regine , Magull Jörg , Noltemeyer Mathias
Published: August 2003

The reaction of LScBr2 (1), LYI2 (3), LHoI2 (4), or LErI2 (5) [L = N,N′′‐(1,3‐dimethyl‐1,3‐propanediylidene)bis(N′,N′‐diethyl‐1,2‐ethanediamine)] with Me3SnF was investigated. Treatment of 1 with Me3SnF results in the formation of (Me3BrSn‐μ‐F)2LSc (2) while compounds 3−5 give [LSnMe2][Me3SnI2] (6) as the only product that could be isolated and characterized. Metathesis reactions of 1 with AgSO3CF3 led to LSc(SO3CF3)2 (7). Compounds 1, 2, 6 and 7 were characterized by single‐crystal X‐ray structural analysis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Monoarylated Fluoromesitylpalladium Complexes
Authors: Bartolomé Camino , Espinet Pablo , Martín‐Alvarez Jose M. , Villafañe Fernando
Published: August 2003

Monoarylated complexes [PdCl(Fmes)(L‐L)] [Fmes = 2,4,6‐tris(trifluoromethyl)phenyl or fluoromesityl] and trans‐[PdCl(Fmes)L2] have been obtained by arylation of [PdCl2(L‐L)] (L‐L = tmeda) or trans‐[PdCl2L2] (L = SMe2), by splitting the bridging chloro ligands in [Pd(μ‐Cl)(Fmes)(NCMe)]2 {L‐L = 4,4′‐Me2bipy, biquinolyl (2,2′‐biquinoline), OPPhPy2‐N,N′, (OH)(CH3)CPy2‐N,N′, dppe, pte [1,2‐bis(phenylthio)ethane]; L = 4‐pic}, or by substitution of the diolefin in [PdCl(Fmes)(COD)] (L = tBuNC). A 1:1 ratio of [Pd(μ‐Cl)(Fmes)(NCMe)]2 and monodentate ligands affords [PdCl(Fmes)(NCMe)L] (L = 2,6‐lut, 3,5‐lut, PPh3), whereas a 1:1 mixture of [{PdCl(Fmes)(NCMe)}2(μ‐dppe)] and [PdCl(Fmes)(dppe)] is obtained with dppe under mild conditions. The precursor [Pd(μ‐Cl)(Fmes)(NCMe)]2 is generated by boiling under reflux [PdCl(Fmes)(COD)] in MeCN, and has been used to obtain various binuclear monoarylated complexes [Pd(Fmes)(μ‐X)L]2 [X = Br, L = MeCN, P(o‐Tol)3; X = Cl, L = CO, 4‐pic, 3,5‐lut, P(o‐Tol)3]. Other [Pd(Fmes)(μ‐X)L]2 complexes have been obtained from trans‐[PdCl(Fmes)(SMe2)2] (X = Cl, L = tht, SMe2, PPh3) and from K[Pd4(Fmes)4I5] [X = I, L = P(o‐Tol)3]. Despite the steric hindrance imposed by the Fmes ligand (ortho effect), the ligand‐substitution reactions are suggestive of associative mechanisms. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, Structure and Chemical Transformations of Ethynylgermatranes
Authors: Lukevics Edmunds , Arsenyan Pavel , Belyakov Sergey , Pudova Olga
Published: August 2003

Ethynylgermatranes have been prepared from monosubstituted acetylenes by a three‐step synthesis without isolation of the hydrolytically unstable intermediate chlorogermanes and ethoxygermanes. Boiling an equimolar mixture of tetrachlorogermane Cl4Ge, acetylene RC≡CH and triethylamine in hexane leads to germylation of the Csp−H bond and the formation of ethynyl‐substituted trichlorogermanes. Subsequent alkoxylation of chlorogermanes by ethanol in the presence of triethylamine affords triethoxygermanes that then take part in transalkoxylation with triethanolamine to give ethynylgermatranes. The molecular structures of all ethynylgermatranes and the hexacarbonyldicobalt complex of 1‐heptynylgermatrane have been determined by X‐ray crystallography. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
1,2‐Bis‐N‐[2′‐(diphenylphosphanyl)benzoyl]diaminobenzene, a New Chelating Ligand with Versatile Coordination Properties
Authors: Burger Sylvain , Therrien Bruno , Süss‐Fink Georg
Published: August 2003

1,2‐Bis‐N‐[2′‐(diphenylphosphanyl)benzoyl]diaminobenzene (dppbH; 1) was prepared by peptidic coupling and shown to exist, in the solid state, in the form of hydrogen‐bonded dimers by single‐crystal X‐ray structure analysis. As expected, 1 reacts with [MCl2(cod)] (M = Pd, Pt; cod = cyclooctadiene) to form square‐planar complexes. However, in the case of palladium [PdCl2(dppbH)] (2) is obtained, while in the case of platinum [Pt(dppb)] (3) is formed. Thus, the nature of the metal induces a completely different coordination mode: In 2, the dppbH ligand only coordinates through the two phosphorus atoms, while in 3 a dppb ligand, formed by deprotonation of the two amino functions in dppbH, coordinates through the two phosphorus atoms and through the two nitrogen atoms. The single‐crystal X‐ray analyses of the two square‐planar complexes reveal 2 to contain the two phosphorus atoms in a trans coordination mode and 3 to contain the two phosphorus atoms in a cis coordination mode. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Cover Picture: Heteronuclear Metal−Metal Contacts between Gold(I) and Group‐11, ‐12, and ‐13 Centers (Eur. J. Inorg. Chem. 17/2003)
Authors: Bardajía Manuel , Laguna Antonio
Published: August 2003

The cover picture shows a disc that contains a suspension of the complex [(C6F5)2Au{μ‐Ag(OClO3)}Au(C6F5)2] (solid) (Figure 1 in the Microreview) under ultraviolet light. The border of the disc is cooled with liquid nitrogen to a temperature close to 77 K and the centre of the disc is at room temperature. The luminescence and the colour of the complex changes from red (near 77 K), through orange and yellow, to green (room temperature). Details are discussed in the Microreview by M. Bardajía and A. Laguna on p. 3069 ff.
Stemflow estimation in a redwood forest using model‐based stratified random sampling
Authors: Lewis Jack
Published: August 2003

Model‐based stratified sampling is illustrated by a case study of stemflow volume in a redwood forest. The approach is actually a model‐assisted sampling design in which auxiliary information (tree diameter) is utilized in the design of stratum boundaries to optimize the efficiency of a regression or ratio estimator. The auxiliary information is utilized in both the design and estimation phases. Stemflow and its variance were modelled as powers of diameter and a generalized non‐linear least squares model was used to estimate the exponents and to impute values for missing storm events prior to application of the ratio estimator. The advantage of the ratio estimator over standard stratified sampling formulas is greatest for species in which stemflow is strongly dependent on diameter. With measurements on 24 trees in a 1‐hectare stand, annual stemflow was estimated with coefficients of variation of 9 per cent and 10 per cent in 2 years of study. Striking stemflow differences were found between species. Copyright © 2003 John Wiley & Sons, Ltd.
On the distribution of wildfire sizes
Authors: Schoenberg Frederic Paik , Peng Roger , Woods James
Published: August 2003

A variety of models for the wildfire size distribution are examined using data on Los Angeles County wildfires greater than 100 acres between 1950 and 2000. In addition to graphs and likelihood criteria, Kolmogorov–Smirnoff and Cramer–von Mises statistics are used to compare the models. The tapered Pareto distribution appears to fit the data quite well and offers some advantages over the untapered Pareto distribution, while alternatives including the lognormal, half‐normal, exponential and extremal distributions fit poorly. The size distribution appears to be quite stable over the examination period, though inspection of the transformed wildfire sizes for the tapered Pareto reveals some limited trend in the residuals, indicating a very slight gradual decrease in the average fire size in Los Angeles County over these 50 years. Copyright © 2003 John Wiley & Sons, Ltd.
Space–time modeling of vertical ozone profiles
Authors: Lee Jaeyong , Berger James O.
Published: August 2003

Ozonesondes collect data relevant to ozone level at various altitudes. Modeling these data involves a combination of spatial and temporal modeling. The spatial component can be conveniently modeled as a four component mixture of normal distributions. The (relatively few) parameters of this mixture can then be modeled in a time‐dependent fashion, via a dynamic linear model. Computations are carried out via Markov chain Monte Carlo methods. Copyright © 2003 John Wiley & Sons, Ltd.
A numerical model for the behaviour of masonry under elevated temperatures
Authors: Nadjai A. , O'Garra M. , A. Ali F. , Laverty D.
Published: August 2003

A thermo‐structural finite element model for the behaviour of masonry panels exposed to fire conditions has been developed. The model has been specifically designed to simulate the behaviour of both loaded and unloaded brickwork panels in plane stress, which are subject to various types of temperature distribution associated with typical fire situations. The current model has been evaluated using experimental results from fire tests on half‐ and full‐scale masonry walls exposed to elevated temperature on one face. Analytical and experimental results for the fire tests were basically in good agreement, indicating that reliable results can be achieved provided that accurate material properties and test boundary conditions are known, and that reliable temperature distribution data through the thickness of the wall is available. Copyright © 2003 John Wiley & Sons, Ltd.
Locations of facilities with special programs for older substance abuse clients in the US
Authors: Schultz Susan K. , Arndt Stephan , Liesveld Jill
Published: August 2003

Background

Given the growth of our aging population, developing strategies for managing late‐life alcoholism is increasingly important.

Objective

We compared substance abuse treatment facilities with and without services designed for older adults and explored the location of these services relative to the regional distribution of older adults across the United States.

Methods

A public use dataset from a national survey of facilities offering substance abuse treatment was used to address this issue. This survey included all identified substance abuse/dependence treatment facilities in the US and surveyed the facilities' treatment services, services for special groups, number of clients admitted, type of ownership (e.g. public, private for profit), and whether or not the facility was associated with a hospital, as well as questions about licensure and income sources.

Results

Of the 13 749 responding facilities, relatively few programs (17.7%) were specifically designed for older adults (i.e. over age 65). Facilities with such programs tended to be associated with hospitals, particularly those with a psychiatric inpatient service. Importantly, the number of facilities with special programs for older adults did not correlate with size of the older population in each state.

Conclusion

Despite an increasing need for older adult substance abuse services, there are relatively few programs available designed for this age group. The setting where patients with substance abuse are identified (e.g. in a hospital) may partially explain the pattern of locations of age‐specific programs. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of hippocampal cholinergic deafferentation on learning strategy selection in a visible platform version of the water maze
Authors: Bizon J.L. , Han J.‐S. , Hudon C. , Gallagher M.
Published: August 2003

Recent evidence has suggested that the relative levels of acetylcholine (ACh) between brain structures may be an important factor in the choice of behavioral strategy in settings in which either hippocampal or dorsal striatal brain systems can be employed both effectively and independently (McIntyre and Gold. 1999. Soc Neurosci Abs 25:1388). The current investigation used the neurotoxin 192 IgG‐saporin to deplete the hippocampus of ACh selectively, while leaving ACh in other brain regions, including dorsal striatum, intact. Rats were then trained on a version of the Morris water maze, in which behavioral strategies attributed to the hippocampus and dorsal striatum are placed in direct competition. It was predicted that rats with hippocampal ACh depletion would display a cue bias. Contrary to this prediction, depleting hippocampal ACh did not bias against and, in fact, promoted use of a hippocampal place strategy in this task, as indicated by choice in competition tests and performance on hidden platform training trials. These data add to a growing literature demonstrating that the septohippocampal cholinergic system is not required for accurate spatial learning and suggest a complex role for basal forebrain projections in processing information about the spatial environment. © 2003 Wiley‐Liss, Inc.