bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tissue Doppler gated (TDOG) dynamic three‐dimensional ultrasound imaging of the fetal heart
Authors: Brekke S. , Tegnander E. , Torp H. G. , Eik‐Nes S. H. 
Published: July 2004

AbstractDynamic three‐dimensional (3D) ultrasound imaging of the fetal heart is difficult due to the absence of an electrocardiogram (ECG) signal for synchronization between loops. In this study we introduce tissue Doppler gating (TDOG), a technique in which tissue Doppler data are used to calculate a gating signal. We have applied this cardiac gating method to dynamic 3D reconstructions of the heart of eight fetuses aged 20–24 weeks.The gating signal was derived from the amplitude and frequency contents of the tissue Doppler signal. We used this signal as a replacement for ECG in a 3D‐volume reconstruction and visualization, utilizing techniques established in ECG‐gated 3D echocardiography.The reliability of the TDOG signal for fetal cardiac cycle detection was experimentally investigated. Simultaneous recordings of tissue Doppler of the heart and continuous wave (CW) spectral Doppler of the umbilical artery (UA) were performed using two independent ultrasound systems, and the TDOG signal from one system was compared to the Doppler spectrum data from the other system. Each recording consisted of a two‐dimensional (2D) sector scan, transabdominally and slowly tilted by the operator, covering the fetal heart over approximately 40 cardiac cycles. The total angle of the sweep was estimated by recording a separate loop through the center of the heart, in the elevation direction of the sweep.3D reconstruction and visualization were performed with the EchoPAC‐3D software (GE Medical Systems). The 3D data were visualized by showing simultaneous cineloops of three 2D slices, as well as by volume projections running in cineloop.Synchronization of B‐mode cineloops with the TDOG signal proved to be sufficiently accurate for reconstruction of high‐quality dynamic 3D data. We show one example of a B‐mode recording with a frame rate of 96 frames/s over 20 seconds. The reconstruction consists of 31 volumes, each with 49 tilted frames. With the fetal heart positioned 5–8 cm from the transducer, the sampling distances were approximately 0.15 mm in the beam direction, 0.33° ∼ 0.37 mm azimuth and 0.45° ∼ 0.51 mm elevation. From this single dataset we were able to generate a complete set of classical 2D views (such as four‐chamber, three‐vessel and short‐axis views as well as those of the ascending aorta, aortic and ductal arches and inferior and superior venae cavae) with high image quality adequate for clinical use. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Disappearance of enlarged nuchal translucency before 14 weeks' gestation: relationship with chromosomal abnormalities and pregnancy outcome
Authors: Müller M. A. , Pajkrt E. , Bleker O. P. , Bonsel G. J. , Bilardo C. M. 
Published: July 2004

AbstractObjectiveThe aim of this study was to investigate the natural course of enlarged nuchal translucency (NT) and to determine if its disappearance before 14 weeks' gestation is a favorable prognostic sign in relation to fetal karyotype and pregnancy outcome.MethodsA total of 147 women with increased NT (> 95th centile) at first measurement were included in this study. A second measurement was performed in all cases, at an interval of at least 2 days. Both measurements were taken between 10 + 3 and 14 + 0 weeks. All women underwent chorionic villus sampling or amniocentesis for subsequent karyotyping. In those women with a normal karyotype, a fetal anomaly scan was performed at 20 weeks' gestation. Pregnancy outcome was recorded in all cases. The finding of persistent or disappearing NT enlargement was analyzed in relation to fetal karyotype and pregnancy outcome.ResultsOf the 147 paired measurements, NT remained enlarged at the second measurement in 121 (82%) cases. An abnormal karyotype was found in 35% of these cases. In 26 (18%) fetuses the NT measurement was found to be below the 95th percentile at the second measurement and in only two of them an abnormal karyotype was found (8%). In the 103 chromosomally normal fetuses an adverse outcome (i.e. fetal loss or structural defects) was recorded in 22 fetuses with persistent enlargement (28%) and in four fetuses with disappearing enlargement (17%).ConclusionsDisappearance of an enlarged NT before 14 weeks' gestation is not a rare phenomenon and seems to be a favorable prognostic sign with respect to fetal karyotype. Overall, no significant difference in pregnancy outcome was found between chromosomally normal fetuses with persisting or disappearing NT enlargement. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Prenatal diagnosis of hemifacial microsomia and ipsilateral cerebellar hypoplasia in a fetus with oculoauriculovertebral spectrum
Authors: Martinelli P. , Maruotti G. M. , Agangi A. , Mazzarelli L. L. , Bifulco G. , Paladini D. 
Published: July 2004

AbstractOculoauriculovertebral spectrum, or Goldenhar syndrome, is characterized by varying degrees of prevalently unilateral underdevelopment of craniofacial structures (orbit, ear, mandible) and spinal anomalies. We report the prenatal ultrasonographic diagnosis made at 24 weeks' gestation in a family with a negative history. The prenatal diagnosis was suspected due to the presence of marked hemifacial microsomia and moderate ipsilateral cerebellar hemisphere hypoplasia in the absence of facial clefting. Copyright © 2004 ISUOG. Published by John Wiley & Sons, Ltd.
Phosphorpentachlorid und Trichlorphenol — eine 31P‐NMR‐Studie [1]
Authors: Gloede Jörg , Waschke Regina , Pieper Ursula 
Published: July 2004

AbstractPhosphorpentachlorid reagiert mit 2, 4, 6‐Trichlorphenol in Abhängigkeit vom Verhältnis der Edukte zu 2, 4, 6‐Trichlorphenoxy‐chlorphosphorane.
The Molecular Structures of Di(1‐cyclohepta‐2, 4, 6‐trienyl)sulfane, S(C7H7)2, and its 1:1 Diels‐Alder Adduct with Maleic Anhydride
Authors: Herberhold Max , Liu Jinnan , Milius Wolfgang 
Published: July 2004

AbstractThe reaction of the olefinic thioether S(C7H7)2 (1) with maleic anhydride (a), maleimide (b) and N‐phenyl maleimide (c) leads to 1:1 Diels‐Alder adducts (4a‐c) in which one of the two 1‐cyclohepta‐2, 4, 6‐trienyl substituents has remained intact. In the solid state, both S(C7H7)2 (1) and its 1:1 adduct with maleic anhydride (4a) contain the C7H7 substituents in the boat conformation in axial attachment to the sulfur atom. Addition of maleic anhydride (a) to 1 results in flattening of the remaining boat‐shaped 1‐cyclohepta‐2, 4, 6‐trienyl ring and in a slight increase of the angle at the central sulfur atom from 100.7(1)° in 1 to 103.2(2)° and 102.7(2)° in the two independent molecules 4a and 4a′, respectively, of the adduct.
2‐Dialkyl‐ and 2‐tert‐Butylphenylphosphinophenol(ate) Nickel and Palladium Complexes: Control of E/Z‐Configuration in Bis(P∩O—‐chelates) and Activation of the Nickel Complexes for Polymerization of Ethylene
Authors: Heinicke Joachim , Köhler Martin , Peulecke Normen , Keim Wilhelm , Jones Peter G. 
Published: July 2004

AbstractNickel bis(2‐dialkylphosphinophenolates), detected as the spent form of organonickel 2‐dialkylphosphinophenolate catalysts for the polymerization of ethylene, were studied. In contrast to the impact of the P‐basicity on the catalyst properties, the configuration of bis(2‐dialkylphosphinophenolate) nickel is controlled only by steric effects. Small alkyl substituents favor, as do phenyl groups, square planar cis‐bis(P∩O—‐chelates) while more bulky alkyl groups lead to trans‐isomers. Dicyclohexyl‐ and tert‐butylphenylphosphino groups give rise to borderline cases. Analogous palladium complexes show a slightly smaller effect of the metal size on the cis/trans‐control. Intermediates on the way to PdII bis(P∩O—‐chelates), trans‐dichloro‐bis(phosphinophenol)‐ and chloro‐phosphinophenol phosphinophenolate palladium(II) complexes could be isolated; the crystal structure of one of the latter was determined. The nickel bis(2‐dialkylphosphinophenolates) can be activated as polymerization catalysts, to a limited extent by NiBr2·DME and sodium hydride or triethylsilane in THF, more efficiently by nBuLi or nBuLi / NiBr2·DME.
Hydrolysis of 4‐Nitrophenyl Acetate by a μ2‐OH‐bridged Zinc Complex: Crystal Structure of [Zn(oapy)(OAc)(μ2‐OH)] and [ZnL(μ2‐SO4)]4·6H2O (oapy is 2‐aminopyridine and L is 2, 5, 8‐triaza‐1, 9‐di(2‐fluorozenzyl)nonane)
Authors: Zhu Hai‐Liang , Ma Ji‐Long , Wang Da‐Qi 
Published: July 2004

AbstractTwo new complexes, [Zn(oapy)(OAc)(μ2‐OH)] (1) and [ZnL(μ2‐SO4)]4·6H2O (2), were prepared and structurally characterized, where oapy is o‐aminopyridine, OAc is acetate, and L is 2, 5, 8‐triaza‐1, 9‐di(2‐fluorozenzyl)nonane. The X‐ray structure analysis reveals that 1 crystallizes in the monoclinic system with space group P21/c, with a = 8.849(9), b = 5.391(5), c = 19.733(19)Å, β = 98.467(13)°, V = 931.2(16)Å3, and Z = 4. 1 is a μ2‐OH bridged 1D chain complex along b. The Zn2+ ion is four‐coordinated by one N atom from an oapy, and three O atoms from two hydroxyl groups and an acetate ion, leading to a distorted tetrahedral geometry of Zn2+. 2 crystallizes in space group P1¯ with a = 15.86(3), b = 17.05(3), c = 19.85(4)Å, α = 74.60(4), β = 66.93(3), γ = 65.33(4)°, V = 4456(16)Å3, and Z = 2. Compound 2 is a 1D chain‐like complex linked by μ2‐(O, O′)‐SO4 bridges. Each simplest unit of the complex is a tetranuclear zinc(II) unit. In each unit the four non‐equivalent zinc atoms, are similarly five‐coordinated by three N atoms from L and two O atoms from two sulfate bridges. The coordination geometry of two zinc atoms is trigonal bipyramidal, the other two are in square pyramidal coordination. 1 has obvious catalytic activity to hydrolysis of 4‐nitrobenyl acetate, but 2 does not.
Lanthanide(III) Amidinates with Six‐ and Seven‐Coordinate Metal Atoms
Authors: Richter Joachim , Feiling Jürgen , Schmidt Hans‐Georg , Noltemeyer Mathias , Brüser Wolfgang , Edelmann Frank T. 
Published: July 2004

AbstractThe crystalline lithium N, N′‐diorganoamidinates Li[PhC(NR)2] (1: R = c‐C6H11, 2: R = iPr) and Li[(CF3)3C6H2C(N‐c‐C6H11)2] (3) have been obtained by the reaction of phenyllithium or 2, 4, 6‐tris(trifluoromethyl)phenyllithium, resp., with diorganocarbodiimides R‐N=C=N‐R (R = c‐C6H11, iPr). These amidinates have been used for the synthesis of the homoleptic lanthanide(III) amidinates [PhC(N‐c‐C6H11)2]3Ln (4—6: Ln = Pr, Nd, Sm) and [PhC(NiPr)2]3Pr (7). Seven‐coordinate Lewis‐base adducts of the type [PhC(NSiMe3)2]3Ln(NCPh) (8, 9: Ln = Sm, Eu) have been prepared by addition of benzonitrile to the homoleptic precursors [PhC(NSiMe3)2]3Ln. The compounds 2 (as its THF adduct), 4, 6, 8 and 9 have been structurally characterized by single crystal X‐ray analyses.
Synthesis of the first Pentacarbonyltungsten(0) Complexes with P‐Pentamethyl‐cyclopentadienyl‐substituted 1H‐Phosphirene Ligands: Crystal Structure of [{(Me5C5PC(H)=CPh}W(CO)5]
Authors: Streubel Rainer , Bode Maren , Schiemann Udo , Wismach Cathleen , Jones Peter G. , Monsees Axel 
Published: July 2004

AbstractThe tungsten(0) complex [{Me5C5PC(Ph)=N}W(CO)5] (1) reacts upon heating with alkyne derivatives 3a—e in toluene to form benzonitrile and the complexes [{Me5C5PC(R1)=C(R2)}W(CO)5] (4a—e) (4a: R1 = OEt, R2 = H; 4b: R1 = OEt, R2 = SiMe3; 4c: R1 = Ph, R2 = H; 4d : R1 = Ph, R2 = Ph; 4e: R1, R2 = Et), which were purified by column chromatography (except 4d). In reaction of 1 with 3d the tungsten(0) complex 5, having a 2, 3‐dihydro‐1, 2, 3‐azadiphosphete ligand, is formed in a competing reaction. Spectroscopic and mass spectrometric data of complexes 4a—c, 4e and 5 are discussed. The structures of complexes 4c and 5 were determined by single‐crystal X‐ray diffraction In 4c the three‐membered ring has a C=C bond length of 1.312(3)Å and a C—P—C angle of 43.02(9)°. In 5 the P—P bond length is 2.2866(7)Å; the four‐membered ring is slightly folded (fold angle 15° about P1—C6).
A Novel Ruthenium(III) and Lithium Complex: Synthesis, Crystal Structure, and Magnetic Properties
Authors: Bai Li‐Xia , Liu Xin , Wang Wen‐Zhen , Liao Dai‐Zheng , Wang Qing‐Lun 
Published: July 2004

AbstractA novel complex [Li3{μ‐(H2O)6}(H2O)6]·[RuCl6] has been synthesized and was characterized by single‐crystal X‐ray diffraction. The compound crystallizes in rhombohedral space group R3¯c, with the unit cell parameters a = b = 9.948(2)Å, c = 33.376(14)Å, γ = 120°, V = 2860.5(15)Å3, Z = 6, Dc = 1.918 Mg m—3, μ = 1.703 mm—1, R = 0.0244, wR = 0.0478. The compound consists of a cation, which contains three lithium ions linked by six bridged water molecules, and an anion, which contains a ruthenium(III) ion. The whole complex can be described as a three‐dimensional structure linked by hydrogen bonds between cation and anion. The magnetic properties of the complex have been investigated. The IR, UV‐vis and EPR spectra are studied.
Conjugation of the closo‐Borane Mercaptoundecahydrododecaborate (BSH) to a Tumour Selective Peptide
Authors: Mier Walter , Gabel Detlef , Haberkorn Uwe , Eisenhut Michael 
Published: July 2004

AbstractThe non‐toxic disodium mercaptoundecahydrododecaborate (BSH) is one of the most promising agents known for boron‐neutron‐capture therapy (BNCT). In order to enhance the intratumoral concentration of the boron cluster by receptor mediated endocytosis, a synthetic method for the conjugation of borane clusters to peptides was developed. A Michael addition was performed to link BSH to the thiol reactive maleimido modified Tyr3‐octreotate. Tyr3‐octreotate, synthesized by Fmoc‐solid phase peptide synthesis, is a selective ligand for somatostatin receptors. The modified boron cluster was obtained in 68 % yield after purification. Characterisation of the BSH conjugate was performed with HPLC, MALDI‐TOF and electrospray mass spectrometry. The BSH‐Tyr3‐octreotate conjugate is considered to target receptor‐positive tumours which might further improve the potential of BNCT.
[{ImCH2Br}Br]6 — eine unerwartete Käfigstruktur [1]
Authors: Kuhn Norbert , Abu‐Rayyan Ahmed , Steimann Manfred , Ströbele Markus 
Published: July 2004

AbstractDie Imidazolderivate ImCH2X2 [Im = C7H12N2; X = Br (5), Cl (8)] werden durch Umsetzung des ylidartigen Olefins ImCH2 (3) mit Brom bzw. Hexachlorethan erhalten. Die Kristallstrukturanalyse von 5 zeigt das Vorliegen eines hexameren Kations mit trigonal‐antiprismatischem Br6‐Kern sowie isolierte Bromidionen. In die aus zwei Br3‐Dreiecksflächen und den zugehörigen Imidazolium‐Ringen gebildeten Käfigpaare kann jeweis ein Solvensmolekül S (6: S = CHCl3; 7: S = CH3CN) ohne signifikante Änderung der Atomkoordinaten eingelagert werden. Im Gegensatz zu 5 besteht 8 im festen Zustand aus isolierten Ionen. Die Kristallstrukturen von 5 — 8 werden diskutiert.
On the Reaction of Triaryl Trithioarsenites, (ArS)3As, with Octasulfur
Authors: Haikou Maria N. , Tsivgoulis Gerasimos M. , Ioannou Panayiotis V. 
Published: July 2004

Abstractpara‐Substituted with electron donating or electron withdrawing groups triphenyl trithioarsenites, (ArS)3As, and octasulfur in refluxing carbon disulfide or chloroform do not give the triaryl tetrathioarsenates, (ArS)3As=S, as was claimed in the literature for tris(4‐methylphenyl) tetrathioarsenate. In some cases oxidative decomposition to As2O3 and disulfides ArSSAr was found. When equivalent amounts of the same esters and octasulfur were heated at 105 or 150 °C no AsV compound was detected or isolated and again some esters decomposed to As2O3 and disulfides. These experiments demonstrated that the aromatic trithioarsenites do not react with octasulfur, probably because they cannot open the octasulfur ring. These esters in solution react with octasulfur in the presence of a catalytic (10—20 mol%) amount of triethylamine giving disulfides, As2O3 and colored solids which could not be characterized.
Hg4OF6, das erste Quecksilberoxidfluorid
Authors: Müller Bernd G. , Klein Wilhelm , Jansen Martin 
Published: July 2004

AbstractHg4OF6, das erstmals als Produkt der thermischen Zersetzung von (O2)2Hg2F(SbF6)5 in Form eines zinnoberroten, kristallinen Pulvers beobachtet wurde, läßt sich durch Festkörperreaktion aus den binären Komponenten HgO und HgF2 phasenrein darstellen. Es kristallisiert hexagonal im Ba4OCl6‐Typ (P63mc (Nr. 186), a = 774.57(1), c = 600.75(1) pm, Z = 2, Rietveld‐Profilanpassung, RP = 6.17 %, RwP = 8.00 %).
Ca2[BN2]H: The First Nitridoborate Hydride — Synthesis, Crystal Structure, and Vibrational Spectra
Authors: Somer Mehmet , Yaren Özlem , Reckeweg Olaf , Prots Yurii , Carrillo‐Cabrera Wilder 
Published: July 2004

AbstractCa2[BN2]H was synthesized from a mixture of the binary components Ca3N2, CaH2 and BN (molar ratio 1 : 1 : 2) in a sealed steel ampoule encapsulated in an evacuated silica tube at 1273 K. Ca2[BN2]H crystallizes in the orthorhombic space group Pnma (no. 62) with a = 9.2015(8)Å, b = 3.6676(2)Å and c = 9.9874(12)Å (Z = 4; Pearson symbol oP24). The crystal structure is a filled variant of the Co2P type and can be formulated as Co2P(□t)3(□py)3 ≡ Ca2[N—B—N]H(□t)2(□py)3 (□t and □py = tetrahedral and square‐pyramidal hole, respectively). The d(B—N) bond lengths and bond angle for the linear [N—B—N]3— anion are: d(B—N1) = 1.324(3)Å, d(B—N2) = 1.350(2)Å and ∠N—B—N = 177.2(2)°. The vibrational spectra of Ca2[BN2]H confirm the presence of [N—B—N]3— groups deviating only slightly from the ideal D∞h symmetry. The vibrational frequencies and the ƒ(B—N) force constants are discussed and compared with those of the isotypic compound Ca2[BN2]F.
Oxidative Dimerisierung von Phosphanen und Hinweise auf das intermediäre Auftreten des Phosphinophosphinidens tBu2P—P in Reaktionen von [(η5‐C5H5)2TiCl2] und [(η5‐C5H5)(η5‐C5Me5)TiCl2] mit tBu2P—P(SiMe3)Li und tBu2P—P(Li)—PtBu2. Bildung von Titan(III)‐Fulvalen‐Komplexen
Authors: Baum Elke , Matern Eberhard , Pikies Jerzy , Robaszkiewicz Andrzej 
Published: July 2004

AbstractDie Umsetzungen von [Cp2TiCl2] (Cp = C5H5) mit tBu2P—P(Li)—PtBu2 oder mit tBu2P—P(SiMe3)Li führen zur Bildung von TiIII‐Komplexen wie [Cp2Ti{μ‐Cl}2Li(THF)2] (monoklin C2/c) oder [(Cp2Ti{μ‐Cl})2] und in Gegenwart von PMe3 auch zu [Cp2TiCl(PMe3)]. Gleichzeitig dimerisieren die Phosphanreste zu (tBu2P)2P—P(PtBu2)2 bzw. (tBu2P—PSiMe3)2. Zusammen mit (tBu2P—PSiMe3)2 bilden sich Produkte, die auf das intermediäre Auftreten von tBu2P—P hindeuten.Die Umsetzung von [Cp2TiCl2] bzw. von [Cp(Cp*)TiCl2] (Cp* = C5Me5) mit nBuLi in Gegenwart von tBu2P—P(SiMe3)2 liefert unerwartet die TiIII‐Fulvalen‐Komplexe [{Ti(η5‐C5H5)(μ‐Cl)}2{μ‐(η5‐C5H4‐η5‐C5H4)}] und [{Ti(η5‐C5Me5)(μ‐Cl)}2{μ‐(η5‐C5H4‐η5‐C5H4)}] (triklin, P1¯).
DFT‐Berechnungen an adamantanartigen Phosphoroxid‐sulfiden der allgemeinen Formel P4O10—nSn (n = 1—9)
Authors: Huu Thong Nguyen , Meisel Manfred 
Published: July 2004

AbstractDie vor einer Reihe von Jahren experimentell bei Reorganisationsreaktionen zwischen P4S10 und P4O10 gefundene Stabilität von Isomeren der Phosphoroxidsulfide der allgemeinen Formel P4O10—nSn wurde durch Dichtefunktionaltheorie(DFT)‐Rechnungen bestätigt. Die erhaltenen Daten lassen auch Aussagen über die Chancen einer erfolgreichen Darstellung bisher noch nicht isolierter oder unzureichend charakterisierter Phosphoroxidsulfid‐Isomere zu.
Chemischer Transport fester Lösungen. 14 [1] Der Chemische Transport von GaP und von Mischphasen im System ZnS/GaP
Authors: Locmelis S. , Binnewies M. 
Published: July 2004

AbstractMithilfe chemischer Transportreaktionen (Transportmittel Iod, 1000 → 900 °C) konnten im System ZnS/GaP Mischphasen durch chemischen Transport erhalten werden. Bei 900 °C beträgt die Löslichkeit von ZnS in GaP 7 %, die von GaP in ZnS 10 %. Über den Transport von reinem GaP wird berichtet. Er erfolgt entsprechend der Transportgleichung 2 GaP(s) +GaI3(g) = 2 GaI(g) + 0, 5 P4(g).
Study of the Na2O—MoO3 System. Na6Mo11O36 — a New Oxide with Anatase‐related Structure, and the Crystal Structures of Na2MoO4
Authors: Bramnik K. G. , Ehrenberg H. 
Published: July 2004

AbstractA new sodium molybdate, Na6Mo11O36, has been synthesized, and its crystal structure was determined by single crystal X‐ray diffraction (space group P‐1; a = 7.2722(6)Å, b = 22.376(1)Å, c = 9.6686(8)Å, α = 89.98(1)°, β = 112.12(1)°, γ = 90.29(1)°; Z = 2). The compound can be considered as a new structure type related to the anatase structure. Na2MoO4 exists in four different modifications between room temperature and the melting point. The α‐phase is isostructural with spinel‐type Na2WO4, the γ‐phase with thenardite, Na2SO4 (V), and the δ‐phase with Na2SO4 (I). The diffraction patterns of β‐Na2MoO4 are similar to those of the γ‐phase, but could not be indexed.
Octaethyl‐triphosphadiazenium‐dimethyltrifluorosilicat, [Et3PNPEt2NPEt3]+[SiF3Me2]—
Authors: Ackermann Hartmut , Leo Roland , Massa Werner , Dehnicke Kurt 
Published: July 2004

AbstractXenondifluorid reagiert mit der äquivalenten Menge des silylierten Phosphanimins Me3SiNPEt3 in Acetonitrillösung bei —30 °C unter Bildung von [Et3PNPEt2NPEt3]+[SiF3Me2]— (1), das IR‐spektroskopisch und durch eine Einkristall‐Röntgenstrukturanalyse charakterisiert wird. Raumgruppe P21/n, Z = 4, Gitterkonstanten bei 220 K: a = 1129, 21(8); b = 1729, 06(11); c = 1426, 05(10) pm; β = 99, 628(8)°; R1 = 0, 0450. Das Kation von 1 enthält ein S‐förmiges PNPNP‐Gerüst mit PN‐Abständen von im Mittel 158, 0 pm. Das [SiF3Me2]—‐Anion von 1 ist isostrukturell mit dem bekannten PF3Me2‐Molekül mit den Methylgruppen und einem Fluoroliganden in den λquatorialpositionen des trigonal‐bipyramidal koordinierten Siliziumatoms (lokale Symmetrie C2v).
Syntheses and Structures of the First Examples of Lanthanide Complexes with 6‐Hydroxypicolinic Acid
Authors: Sun Chang‐Yan , Zheng Xiang‐Jun , Jin Lin‐Pei 
Published: July 2004

AbstractThree new complexes [La(HpicO)3(H2O)]n·0.5nH2O (1), [Eu(HpicO)3(H2O)3]n·3nH2O (2), and [Yb(HpicO)3(H2O)5]·4H2O (3) (H2picO = 6‐hydroxypicolinic acid) have been synthesized and characterized by single‐crystal x‐ray diffraction. Complexes 1 and 2 consist of 1D infinite chains, which are further assembled into 3D microporous coordination polymers by hydrogen bonds. Crystal water molecules stay in the channels. The complex 3 is of 3D supramolecular architecture self‐assembled via coordination bonds and hydrogen bonds. In these complexes, the carboxylate groups of HpicO— ligands act as tridentate, bidentate, and monodentate modes to coordinate to lanthanide ions. The thermogravimetric analyses of these complexes show that all coordinated and crystal water molecules are lost at the first weight loss. And final residues are lanthanide oxides.