ChemInform Abstract: Pentacoordinate Carbon in Trigonal-Bipyramidal Symmetry. The Eight-Membered Ring X-Ray Structure of Tetrakis(benzylsodium-N,N,N′,N′-Tetramethylethylenediamine).

1986 ◽  
Vol 17 (34) ◽  
Author(s):  
C. SCHADE ◽  
P. VON RAGUE SCHLEYER ◽  
H. DIETRICH ◽  
W. MAHDI
1989 ◽  
Vol 44 (9) ◽  
pp. 1067-1081 ◽  
Author(s):  
M. Veith ◽  
P. Hobein ◽  
R. Rösler

Chelates of Ge(II) and Sn(II)Symmetrically and unsymmetrically substituted germane- and stannanediyls as well as chelated bis(amino)- or aminooxogermanium- and -tinmonohalides have been obtained from cyclic bis(amino)germane- and stannanediyls by treatment with tert-butylamine, tert-butanol and tert-butylmercaptane. The following compounds have been synthesized: GeX2 (X = OtBu (5), StBu (6)), Sn(StBu), (9), GeXCl (X = N(H)tBu (21), OtBu (22)), SnXCl (X = N(H)tBu (23), OtBu (24), StBu (25), OMe (28)) and Sn(OtBu)Br (27). In the series of the chelates Me2Si(NtBu)(NHtBu)GeCl (13), Me2Si(NtBu)(OtBu)SnX (X = Cl (18), OMe (19)) and the bischelate [Me2Si(NtBu)(OtBu)]2Sn (20) have been prepared. When 18 is allowed to react with aluminiumtrimethyl Me2Si(NtBu)(OtBu)AlClMe is formed, a compound with a center of chirality at the aluminium atom. X-ray structure determinations have been performed on single crystals of 6, 8, 9, 13, 22 and 24. 6, 8, 22 and 24 form molecular dimers with c.n. of 3 at the Ge or Sn atoms, resp. While the tBu-S ligands are syn with respect to the central Ge2S2 ring in 6 (symmetry approaching C2v), the tBu-O ligands are anti to the central Sn2O2 ring in 8 (symmetry Ci). 9 forms a coordination polymer with all Sn atoms in a Ψ-trigonal-bipyramidal and all S atoms in a Ψ-tetrahedral environment. The germanium atom in 13 is coordinated by a chlorine, a λ3- and a λ4-nitrogen atom, the two nitrogen atoms being connected by as dimethylsilyl group. The hydrogen and chlorine atom of 13 are found at the same side of the four-membered chelate ring. The two unsymmetrically substituted, homologous compounds Ge(O/tBu)Cl (22) and Sn(OtBu)Cl (24) are found to form dimers via O→Ge resp. O→Sn bonds. While the chlorine atoms in 22 are syn with respect to the four-membered ring, they are anti in the case of molecule 24.


2017 ◽  
Vol 72 (5) ◽  
pp. 327-334
Author(s):  
Ting-Ting Qian ◽  
Yu-Feng Xie ◽  
Hua-Tian Shi ◽  
Ai-Quan Jia ◽  
Qian-Feng Zhang

AbstractInteraction of AgCl with bis(diphenylphosphino)methane (dppm) in THF/MeCN in the presence of K[PF6] or [Et4N]Br afforded typical trinuclear cationic trigonal-bipyramidal complexes [Ag3(μ3-Cl)2(μ-dppm)3][PF6] (1) or [Ag3(μ3-Br)2(μ-dppm)3][AgBr2] (2), respectively. Treatment of AgBr with bis(diphenylphosphino)ethane (dppe) in THF/MeCN in the presence of [Et4N]Br gave a polymeric complex {[Et4N][Ag2(μ-Br)3(μ-dppe)]}n (3) with a dinuclear {Ag2(μ-Br)3} core. The reaction of AgCl with dppe or bis(diphenylphosphino)propane (dppp) in THF/MeCN in the presence of [Et4N]Cl resulted in the isolation of a dinuclear anionic complex [Et4N]2[(AgCl2)2(μ-dppe)] (4) with one μ-dppe bridge or a dinuclear neutral complex [(AgCl)2(μ-dppp)2] (5) with two μ-dppp bridges and a 12-membered ring, respectively. The structures of complexes 1–5 with the bidentate phosphine ligands were determined by single-crystal X-ray diffraction.


1995 ◽  
Vol 50 (12) ◽  
pp. 1785-1790 ◽  
Author(s):  
Ion Neda ◽  
Michael Farkens ◽  
Axel K. Fischer ◽  
Peter G. Jones ◽  
Reinhard Schmutzler

The reactions of 2-(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2λ3-phosphorinan- 4,6-dione (1), 2-bis(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2A3-phosphorinan- 4,6-dione (2), 2-methoxy-1,3,5-trimethyl-1,3,5-triaza-2λ3-phosphorinan-4,6-dione (3) and 2-trimethylsiloxy-1,3,5-trimethyl-1,3,5-triaza-2λ3-phosphorinan-4,6-dione (5) with hexafluoracetone are described. In the case of 2 and 3 the reaction furnished the spirocyclic compounds 7 and 8. 2-Bis(2-chloroethyl)amino-1,3,5-triphenyl-1,3,5-triaza-2λ3-phosphorinan- 4,6-dione (4) did not react. In the case of 1 and 5 rearrangement reactions took place; the (2-chloroethyl)amino substituent of 1 reacted with one of two equivalents of hexafluoroacetone with formation of the spirocyclic phosphorane 6. The reaction of 5 with tetrabromoorthobenzoquinone gave the phosphoryl compound 9. Compounds 6 - 8 were characterized via their 1H-, 13C-, 19F- and 31P-NMR and mass spectra, compound 9 via its 1H-, 13C- and 31P-NMR and mass spectra. An X-ray crystal structure determination of 8 was conducted; in the six-membered ring the phosphorus atom lies 73 pm out of the plane of the other atoms, and displays trigonal bipyramidal coordination.


1995 ◽  
Vol 50 (7) ◽  
pp. 1130-1134 ◽  
Author(s):  
Michael Veith ◽  
Holger Wolfanger ◽  
Volker Huch

As found by X-ray structure analysis (tBuO)4AlSnCl (1) is monomeric in the crystal and has a central AlO2Sn four-membered ring (Sn -O 2,153(5) Å , Al-O 1,807(7)Å). The corresponding iso-propyl derivative 2 reacts with SnCl2 to yield a coordination polymer (iPrO)4AlSn2Cl3 3 incorporating a new trigonal bipyramidal Sn2Cl3+ cation [angles at tin from 67,18(5) - 83,90(5)°]. 3 reacts with moisture to give the compound [(iPrO)5Cl2Al2]2O2Sn4Cl2 (4) which has a central O2Sn4Cl2-cluster of approximately D2h symmetry with four-coordinate η4-bridging chlorine atoms.


2011 ◽  
Vol 696 (11-12) ◽  
pp. 2420-2428 ◽  
Author(s):  
José María Rivera ◽  
Susana Rincón ◽  
Norberto Farfán ◽  
Rosa Santillan
Keyword(s):  

2011 ◽  
Vol 34 (5-6) ◽  
pp. 127-130 ◽  
Author(s):  
Yaya Sow ◽  
Libasse Diop ◽  
Kieran C. Molloy ◽  
Gabrielle Kociok-Köhn

Abstract The title compounds [R2NH2][C2O4SnMe3](R=i-Bu, Cy), in which tin atoms adopt a distorted trigonal bipyramidal configuration, have been prepared and submitted to an X-ray diffraction study. These compounds have been obtained from the reaction of (Cy2NH2)2C2O4·H2O or (i-Bu2NH2)2C2O4 with SnMe3Cl. In both [R2NH2][C2O4SnMe3] compounds, the trans complex has an almost regular trigonal bipyramidal geometry around the tin atom. The SnMe3 residues are connected as a chain with bridging oxalate anions in a trans-SnC3O2 framework, the oxygen atoms being in axial positions. The cations connect linear adjacent chains through NH…O hydrogen bonds giving layered structures.


1965 ◽  
Vol 20 (9) ◽  
pp. 1117-1121 ◽  
Author(s):  
K. Möbius

The stereochemical structure of aromatic hydrocarbons in solution being overcrowded with hydrogen atoms is not known with certainty, because the conventional X-ray and electron diffraction methods are suitable only for samples in the crystalline and vapor phase. Using EPR spectroscopy for the aromatic hydrocarbon radicals biphenyl (—), phenanthrene (—) and pentaphenylcyclopentadienyl (PPCPD) innermolecular twist and bond angles could be determined by means of hfssplittings and g-factors. Stably solvated biphenyl radical ions are found to have twist angles of 38 ±2°; phenanthrene ions turn out to be planar but change their angles of hybridization at particular positions; in the PPCPD radical the phenyl rings oscillate with small amplitude around planes orthogonal to the five-membered ring.


1993 ◽  
Vol 4 (2-3) ◽  
pp. 271-278 ◽  
Author(s):  
Yande Huang ◽  
Alan E. Sopchik ◽  
Atta M. Arif ◽  
Wesley G. Bentrude

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