Showing papers by "George M. Sheldrick published in 1988"
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TL;DR: In this paper, the Rontgenstrukturanalyse mitgeteilt in den Amidinatokomplexen 4a-f, 5a and 5b.
Abstract: PhC(NSiMe3)2Li (3b) reagiert mit SiCl4, SnCl4, Me2SnCl2, Ph2SnCl2, TiCl4, ZrCl4, MoO2Cl2 und WO2Cl2 unter Bildung von LiCl zu den Amidinatokomplexen 4a–f, 5a und 5b. Von 4e und 5a wird die Rontgenstrukturanalyse mitgeteilt.
98 citations
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41 citations
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TL;DR: In this paper, a bicyclic compound with fourfold [F2Li(THF)N] and twofold [NLiN] coordinated lithium was obtained and the NMR spectra in solution showed an equilibration of the H, C, F and Si atoms.
38 citations
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TL;DR: In this paper, a complexe (DBP)Cr(CO) 5 cristallise avec le groupe d'espace P2 1 /c and its structure is affinee jusqu'a 0,070.
32 citations
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TL;DR: In this paper, the reaction of the difluorosilanes with lithiated pentafluoroanilines was studied, and the crystal structure determination of 3 shows lithium coordinated by two THF and one nitrogen; short Li··F interactions with F(Si) and with an ortho-F(C) of the C6F5 group were also observed.
Abstract: Fluorsilylpentafluoraniline [R2SiFNHC6F5, R = CMe3 (1), CHMe2 (2)] entstehen in der Reaktion der Difluorsilane mit lithiiertem Pentafluoranilin. 1 und 2 reagieren mit n-C4H9Li zu ihren Lithiumverbindungen (3, 4) und C4H10. Die Kristallstrukturanalyse von 3 zeigt Lithium mit 2 THF und einem Stickstoff koordiniert; kurze Li··F-Wechselwirkungen werden mit F(Si) und mit einem ortho-F(C) der C6F5-Gruppe beobachtet.
Lithium N-(Fluorosilyl)pentafluoroanilines - Synthesis and Crystal Structure
Fluorosilylpentafluoroanilines [R2SiFNHC6F5, R CMe3 (1); CHMe2 (2)] are obtained in the reaction of the difluorosilanes with lithiated pentafluoroanilines. 1 and 2 react with n-C4H9Li to give their lithium compounds (3, 4) and C4H10. The crystal structure determination of 3 shows lithium coordinated by two THF and one nitrogen; short Li··F interactions with F(Si) and with an ortho-F(C) of the C6F5 group were also observed.
32 citations
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27 citations
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21 citations
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TL;DR: Synthese du compose du titre a partir de l'oxytrichlorure de Vanadium (V) et du bis-trimethylsilylamino diphenyl trimethylsilimino phosphorane.
Abstract: Synthese du compose du titre a partir de l'oxytrichlorure de Vanadium (V) et du bis-trimethylsilylamino diphenyl trimethylsilylimino phosphorane. Etude de sa structure cristalline
19 citations
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TL;DR: Cyclisation of methyl-7 octadiene-1,6dicarboxylates -1,1 de methyle en isopropenyl-2 cyclopentanemalonates de dimethyle as mentioned in this paper.
Abstract: Cyclisation de methyl-7 octadiene-1,6dicarboxylates-1,1 de methyle en isopropenyl-2 cyclopentanemalonates de dimethyle
16 citations
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TL;DR: In this paper, the structure of CF3CN3S2Cl2 (1) and Me2NSiMe3 (2) is obtained by 1,3-substitution with N,N′-bis-silylated sulfur diimides (Me3SiN)2S and Me3SiNs2SX2(X2 = Et2, C4H8) and the urea derivative [Me3NiN(Me)]2CO.
Abstract: Durch Umsetzung von CF3CN3S2Cl2 (1) mit Me2NSiMe3 wird das Aminoderivat CF3CN3S2(NMe2)2) (2) erhalten, mit den N,N′-Bissilylierten Schwefeldiimiden (Me3SiN)2S bzw. (Me3SiN)2SX2(X2 = Et2, C4H8) und dem Harnstoffderivat [Me3SiN(Me)]2CO entstehen durch 1,3-Substitution die entsprechenden Bicyclen CF3CN5S3 (3), CF3CN5S3Et2 (4), CF3CN5S3C4H8 (5) und CF3CN3S2[MeN)2CO] (7). Von 2 und 3 wurden die Strukturen durch Rontgenbeugung bestimmt. Die Bindungsverhaltnisse in den mono- und bicyclischen Derivaten werden in Abhangigkeit von C- und S-gebundenen Substituenten diskutiert und mit MNDO-Rechnungen verglichen.
Syntheses, Structures, and Bond Relationships in Mono- and Bicyclic 1,3,2,4,6-Dithiatriazines
From CF3CN3S2Cl2 (1) and Me2NSiMe3 the amino derivative CF3CN3S2(NMe2)2) (2) is obtained. By 1,3-substitution with N,N′-bis-silylated sulfur diimides (Me3SiN)2S and (Me3SiN)2SX2(X2 = Et2, C4H8) and the urea derivative [Me3SiN(Me)]2CO the bicyclic systems CF3CN5S3 (3), CF3CN5S3Et2 (4), CF3CN5S3C4H8 (5) and CF3CN3S2[MeN)2CO] (7). are formed. The structures of 2 and 3 are determined by X-ray diffraction. Bonding relationships in the mono- and bicyclic derivatives are discussed with respect to the substituents at C and S compared with MNDO calculations.
15 citations
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TL;DR: In this paper, a reaction du dimere avec le phenyl trifluoro silane donne le tetraaza-1,3,5,7 pentasila-2,4,6,8,9 bicyclo.
Abstract: L'octamethylcyclotetrasilazane traite par le butyllithium donne le derive dilithie sous forme de dimere, les 2 cycles etant lies par un cycle symetrique (LiN) 2 . La reaction du dimere avec le phenyl trifluoro silane donne le tetraaza-1,3,5,7 pentasila-2,4,6,8,9 bicyclo [3.3.1] nonane correspondant
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TL;DR: In this paper, the reaction of trichloro-phenylphenylsilane with LiNHCMe3 was investigated, and the cyclotrisilazan was shown to be the main product of the reaction.
Abstract: Aminochlorsilane [RSiCl2NHCMe3, R Cl (1), H (2)] werden durch die Reaktion der Chlorsilane mit LiNHCMe3 erhalten. HSiCl2N(iso-Bu)SiMe3 (3) entsteht in der Reaktion von HSiCl3 mit LiN(iso-Bu)SiMe3. HSiCl3 reagiert mit LiN(CMe3)SiMe3 unter LiCl- und Me3SCl-Abspaltung zum Cyclodisilazan [(HSiClNCMe3)2 (4)]. Neben C6H5SiCl2N(CMe3)SiMe3 (5) ist C6H5SiCl2NHCMe3 (6) das Hauptprodukt der Reaktion von Trichlorphenylsilan mit LiN(CMe3)SiMe3. 3 verliert thermisch Me3SiCl. Es entsteht das Cyclotrisilazan [(HSiClNiso-Bu)3 (7)]. 5 verliert thermisch iso-Butan unter Bildung von C6H5SiCl2NHSiMe3 (8). 1, 2 und 6 reagieren mit n-C6H9Li unter Butan- und LiCl-Abspaltung zu den Cyclodisilazanen [(RSiClNCMe3)2, R H (4), Cl (9), C6H5 (10)]. 4 wird durch NaF zu (HFSiNCMe3)2 (11) fluoriert. Die Alkoholyse von 4 fuhrt zur Bildung von [(H(RO)SiNCMe3)2, R Me (12), C6H5 (13)], die Aminolyse zu [(H(R2N)SiNCMe3)2, R Me (14), C2H5 (15)]. Nur ein Chloratom von 4 wird in der Reaktion mit H2NCMe3 substituiert (16). Mit Lithium reagiert 4 zum 1,3,6,8,10,12-Hexa-aza-2,4,5,7,9,11-hexasila-dispiro[4.1.4.1]-dodecan (17). Die Kristallstruktur von 17 wird mitgeteilt.
Two Ways to Si-functional Cyclosilanes — Crystal Structure of 1,3,6,8,10,12-Hexa-aza-2,4,5,7,9,11-hexasila-dispiro [4.1.4.1]dodecan
Aminochlorosilanes [RSiCl2NHCMe3, R Cl (1), H (2)] are obtained in the reaction of the chlorosilanes with LiNHCMe3. HSiCl2N(iso-Bu)SiMe3 (3) is formed in the reaction of HSiCl3 and LiN(iso-Bu)SiMe3. HSiCl3 reacts with LiN(CMe3)SiMe3 under LiCl and Me3SiCl elimination to give the cyclodisilazane [(HSiClNCMe3)2 (4)]. In addition to C6H5SiCl2N(CMe3)SiMe3 (5), the main product of the reaction of trichloro-phenylsilane with LiN(CMe3)SiMe3 is C6H5SiCl2NHCMe3 (6). 3 loses Me3SiCl thermally, giving the cyclotrisilazane [(HSiClNiso-Bu)3 (7)]. 5 loses iso-butane thermally with formation of C6H5SiCl2NHSiMe3 (8). 1, 2 and 6 react with LiC4H9 under butane and LiCl elimination to give the cyclodisilazes [(RSiClNCMe3)2, R H (4), Cl (9), C6H5 (10)]. 4 is fluorinated to (HSiFNCMe3)2 (11) by NaF. The alcoholysis of 4 leads to the formation of [(H(RO)SiNCMe3)2, R Me (12), C6H5 (13)], the aminolysis to [(H(NR2)SiNCMe3)2, R Me (14), C2H5 (15)], only one chloro atom of 4 is substituted in the reaction with H2NCMe3 (16). 4 reacts with lithium to give the 1,3,6,8,10,12-hexa-aza-2,4,5,7,9,11-hexasila-dispiro[4.1.4.1]dodecan (17), for which the crystal structure is reported.
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TL;DR: In this article, the X-ray structure analysis of F4W(NSPh2) has been confirmed by an Xray analysis of WF6 with 1 in a 1:1 molar ratio.
Abstract: Aus Ph2SNH wird mit Me3SiNMe2 durch Metathese S,S-Diphenyl-N-(trimethylsilyl)sulfimin (1) erhalten. WF6 reagiert mit 1 im Molverhaltnis 1:1 zu F5WNSPh2 (2) und im Molverhaltnis 1:2 zu F4W(NSPh2)2 (3). Von 3 wird eine Rontgenstrukturanalyse vorgelegt.
Preparation of S, S-Diphenyl-N-(trimethylsilyl)sulfimine and Reactions with Tungsten Hexafluoride - X-Ray Structure Analysis of F4W(NSPh2)
Ph2SNH reacts with Me3SiNMe2 to give S,S-diphenyl-N-(trimethylsilyl)sulfimine (1) in a metathesis. Reaction of WF6 with 1 in a 1:1 molar ratio leads to F5WNSPh2 (2); a 1:2 molar ratio results in the formation of F4W(NSPh2)2 (3). The structure of 3 is confirmed by an X-ray analysis.
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TL;DR: In this article, the preparation and characterization of compounds of composition Cl6-xW(OCH2CF3)x (x = 1−6) and X4W[OC(CH3) (CF3)]2 (X = Cl,F) together with 19F NMR spectra are reported.
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TL;DR: Several one-and two-dimensional techniques have been used to assign the 1H and 13C NMR spectra of the cyclic heptadepsipeptide didemnin A in DMSO as discussed by the authors.
Abstract: Several one- and two-dimensional techniques have been used to assign the 1H and 13C NMR spectra of the cyclic heptadepsipeptide didemnin A in DMSO. The composition and sequence of the amino acid residues was known beforehand and could be confirmed by heteronuclear proton–carbon long-range couplings using the COLOC experiment and a recently proposed new inverse technique using Gaussian-shaped pulses. The aliphatic methyl resonances of the isostatin, hydroxyisovalerylpropionyl, N-methylleucine and leucine residues were assigned by means of the TOCSY and NOESY techniques. Aliphatic carbon assignment was performed by inverse correlation via heteronuclear double quantum coherence.
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TL;DR: The reactions of Ag[AsF6] or Ag[SbF6], with ClCN, BrCN, and ICN yield the complexes [Ag(NCCl)2][AsF 6], [AgNCCl]2][SbC 6], Ag(NCBr)2] and [AgNCl] as discussed by the authors.
Abstract: The reactions of Ag[AsF6] or Ag[SbF6] with ClCN, BrCN, and ICN yield the complexes [Ag(NCCl)2][AsF6], [Ag(NCCl)2][SbF6], [Ag(NCBr)2][AsF6], [Ag(NCBr)2][SbF6], and [Ag(NCl)2][AsF6] The salt [Ag(NCCl)2][SbF6] was characterized by an X-ray single-crystal structure investigation The cation is monomeric The cyanogen halide is bonded to the silver through nitrogen, with Ag–N 2140(4)A The co-ordination geometry at silver is exactly linear
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TL;DR: In this article, a complexe (Ph 3 PNInCl 2 OCHNMe 2 ) 2 cristallise avec le groupe d'espace P2 1 /n.
Abstract: Le complexe (Ph 3 PNInCl 2 OCHNMe 2 ) 2 cristallise avec le groupe d'espace P2 1 /n. Affinement de la structure jusqu'a 0,034. Les complexes (Ph 3 PN) 2 Sn 2 Cl 4 •2MeCN et (Ph 3 PNFeCl 2 ) 2 cristallisent avec le groupe d'espace P1. Affinement de la structure jusqu'a 0,062 et 0,054 respectivement
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TL;DR: Preparation du veticadinol grâce a la condensation de Knoevenagel du malonate de diethyle et du R-citronellal as mentioned in this paper.
Abstract: Preparation du veticadinol grâce a la condensation de Knoevenagel du malonate de diethyle et du R-citronellal
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TL;DR: In this paper, the lithium salt of the aminofluorosilane (CMe3)2SiFNH2 reacts with Me3SnCl to give the mixed silyl- and stannyl-sbustituted amine.
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TL;DR: In this paper, the reaction of (Et2N)3 PCH2 with MOCl4 in a solvent proceeds with formation of the [(Et 2N) 3 PCH ]+ cation.
Abstract: Abstract (Et2N)3 P=CH2 reacts with NbCl5 , WCl6 or WF6 under C-C bond formation to give the phosphonium cation [(Et2N)3 PCH2]2 2+ · [(Et2N)3PCH2]22+ [WCl6 ]2 - was isolated in a crystalline form and investigated by X-ray analysis. The reaction of (Et2N)3 P=CH2 with MOCl4 in a solvent proceeds with formation of the [(Et2N)3 PCH ]+ cation.
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TL;DR: Me2SN2P2Ph4M(CO)4 complexes have been synthesized from Me2S(NPPh2)2 and C7H8M( CO)4 as mentioned in this paper.
Abstract: Abstract Me2SN2P2Ph4M(CO)4 complexes (1) (M: 1 a Cr, 1 b Mo, 1 c W) have been synthesized from Me2S(NPPh2)2 and C7H8M(CO)4 . 1a-1c are stable at room temperature, 1 b crystallizes in the space group P21212 with cell constants a = 2486.3(2); b = 1488.8(1); c = 882.0(1) pm.
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TL;DR: In this paper, a light red crystal from NH₄Br and NbBr ₅ in a sealed glass ampoule at 420 °C, whereby the oxygen presumably originates from the glass surface.
Abstract: (NH₄)NbOBr₄ is obtained as air sensitive, light red crystals from NH₄Br and NbBr ₅ in a sealed glass ampoule at 420 °C, whereby the oxygen presumably originates from the glass surface. The compound crystallizes in the monoclinic space group C2/m with a = 1269.9(1), b = 1384.7(2). c = 773.0(2) pm, β = 114.44(2)° and Z = 6. The structure is built up by NH⁴⁺ cations and polymeric NbOBr₄ anions. Symmetrical linear oxo bridges with Nb-O = 199 pm connect square planar NbBr₄ units to form endless chains arranged in planes parallel (010). Neighbouring NbBr₄ units are in eclipsed as well as staggered orientations. The NH₄⁺ cations are located between the planes of parallel NbOBr₄ ⁻ chains. The vibrational frequencies of the IR and Raman spectrum are assigned.
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TL;DR: The reaction of Ph3AsCl2 (1) and N(SiMe3)3 (2) yields [Ph3As-N-AsPh3]+Cl (3) as a crystalline white solid, soluble in CH3OH and acetone.
Abstract: Abstract The reaction of Ph3AsCl2 (1) and N(SiMe3)3 (2) yields [Ph3As-N-AsPh3]+Cl (3) as a crystalline white solid, soluble in CH3OH and acetone. 3 might be used to stabilize unusual anions. It crystallizes as a 1:1 toluene adduct in the space group C2/c with a - 1585.3(3). b = 1058.7(2). c = 2266.3(4) pm. β = 94.40(2)° and Z = 4. The cation in 3 lies on a crystallographic two-fold axis with As-N-As 123.9(1)°. As-N 174.9(3). and As-C 196.7(5). 197.6(5). 193.2(5) pm.
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TL;DR: In this article, the authors describe the crystal structure of Ca[C6(i-C3H7)2O4H]2·2/3H2O were grown in aqueous silica gel.
Abstract: Abstract Dark, hydrophobic single crystals of Ca[C6(i-C3H7)2O4H]2·2/3H2O were grown in aqueous silica gel. Infinite layers parallel to (001) formed by Ca2+ and [C6(i-C3H7)2O4H]- are the main feature of the crystal structure. Ca2+ is coordinated in two different manners. Ca(1) has CN7: the coordination polyhedron is a slightly distorted capped trigonal antiprism made up by one water molecule and six oxygen atoms (O(1), O(2)) of the anions which chelate Ca(1). The mean Ca(1)-O distance is 238.9 pm. The coordination polyhedron of Ca(2) is a distorted octahedron formed by six anions acting as monodentate ligands via O(3): Ca(2)-O(3) 227.3 pm. In one half of the [C6(/-C3H7)204H] anion the bonding geometry resembles that of the corresponding dianions, but in the other half the bond lengths are very similar to those observed in free 2,5-dihydroxy-p-benzoquinones. The remaining H atom of the anion is involved in strong intramolecular hydrogen bonding as well as in an intermolecular hydrogen bond.
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TL;DR: In this paper, the X-ray crystal structure analyses of 3 and 5 are reported and the reaction with (Me2N)3P leads to the 2-aza-diene.