Röntgenstrukturuntersuchungen an Trimethylsilylaluminiumverbindungen / X-Ray Crystal Study of Trimethylsilylaluminium Compounds

1983 ◽  
Vol 38 (1) ◽  
pp. 34-41 ◽  
Author(s):  
Lutz Rösch ◽  
Gerald Altnau ◽  
Carl Krüger ◽  
Y.-H. Tsay
Keyword(s):  
Structure Analysis ◽  
Ion Pair ◽  
Molecular Structures ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Contact Ion Pair ◽  
Linear Chains ◽  
Pair Interactions

Abstract Structure, Tris(trimethylsilyl)aluminium, Sodium-tetrakis(trimethylsilyl)aluminate The crystal and molecular structures of three trimethylsilylaluminium compounds -tris(trimethylsilyl)aluminium coordinated to a diethylether molecule (1), sodium-tetrakis-(trimethylsilyl)aluminate coordinated to two toluene molecules (2b) and unsolvated sodium-tetrakis(trimethylsilyl)aluminate (2a) -have been determined by X-ray structure analysis. In all three compounds the aluminium is tetrahedrally coordinated, the Al-Si-distances lying between 2.44 and 2.49 Å. (1) is monomeric and (2a) and (2b) form linear chains resulting from contact-ion pair interactions.

Untersuchungen an Stickstoff-Brom-Verbindungen, IV / Studies on Nitrogen-Bromine Compounds, IV

1977 ◽  
Vol 32 (12) ◽  
pp. 1416-1420 ◽  
Author(s):  
Omar Jabay ◽  
Hans Pritzkow ◽  
Jochen Jander
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Structure Analysis ◽  
Electron Acceptors ◽  
Molecular Structures ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Solid Nitrogen ◽  
Intermolecular Contacts

The crystal and molecular structures of N-bromobenzamide (NBB), N-bromosuccinimide (NBS), and N,N-dibromobenzenesulfonamide (NBBS) were determined by X-ray structure analysis. The nitrogen atoms in NBB and NBS have a trigonal planar coordination (sp2) and the N—Br distances lie in the same range (1.82 A, 1.84 A). The N—Br distance in NBBS, where the nitrogen atom is sp3-hybridized, is somewhat longer (1.88 A). In these structures the molecules are connected by O···H—N (NBB), O···Br—N (NBS) or N···Br—N (NBBS) intermolecular bonds forming endless chains; positivated hydrogen atoms or, in case that they are absent, positivated bromine atoms act as electron acceptors with oxygen or sp3- hybridized nitrogen atoms. These results suggest, that in solid nitrogen tribromide, the crystal structure of which cannot be determined, the nitrogen atoms will be sp3-hybridized and intermolecular contacts via N—Br···N will occur.

Beiträge zur Chemie des Schwefels, 116 [1]Kristall-und Molekülstrukturen von 1.2.4.5-Benzotetrathiepin und 3-Methyl-1.2.4.5-benzotetrathiepin / Contributions to the Chemistry of Sulfur, 116 [1]Crystal and Molecular Structures of 1,2,4,5-Benzotetrathiepine and 3-Methyl-1,2,4,5-benzotetrathiepine

1979 ◽  
Vol 34 (3) ◽  
pp. 426-430 ◽  
Author(s):  
F. Fehér ◽  
B. Engelen
Keyword(s):  
Structure Analysis ◽  
Spectroscopic Data ◽  
Membered Ring ◽  
Molecular Structures ◽  
Methyl Group ◽  
Chair Form ◽  
X Ray ◽  
Crystal And Molecular Structures

Abstract The structures of 1,2,4,5-benzotetrathiepine and 3-methyl-1,2,4,5-benzotetrathiepine were determined by X-ray structure analysis. The constitution of the molecules, which was proposed by way of spectroscopic data, could be verified. The conformation of the seven-membered rings is the chair form. The position of the methyl group in 3-methyl-1,2,4,5-benzotetrathiepine is equatorial with respect to the seven-membered ring. Details of the conformations are discussed. Bond distances and angles are compared with those in other molecules, which have similar structures.

Newμ-Oxo Octanuclear Complexes of 3d Elements Stabilized by Dialkylcarbamato Ligands. Synthesis and X-ray Crystal and Molecular Structures†

2002 ◽  
Vol 41 (11) ◽  
pp. 2814-2816 ◽  
Author(s):  
Daniela Belli Dell'Amico ◽  
Consuelo Bradicich ◽  
Fausto Calderazzo ◽  
Alessandro Guarini ◽  
Luca Labella ◽  
...  
Keyword(s):  
Molecular Structures ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
3D Elements

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

Synthesis and resolution of an asymmetric arsonium cation. Crystal and molecular structures of (R)-Benzyl(methyl)(4-methylphenyl)(naphthalen-1-yl)- arsonium bromide and hexafluorophosphate

1984 ◽  
Vol 37 (6) ◽  
pp. 1171 ◽  
Author(s):  
DG Allen ◽  
CL Raston ◽  
BW Skelton ◽  
AH White ◽  
SB Wild
Keyword(s):  
Ion Exchange ◽  
Absolute Configuration ◽  
Optically Active ◽  
Molecular Structures ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Ion Exchange Column ◽  
Optically Pure

The (�)-benzyl(methyl)(4-methylphenyl)(naphthalen-1-yl)arsonium cation has been synthesized and subsequently resolved by fractional crystallization of monohydrogen [R-(R*,R*)]-2,3-bis(benzoyloxy)- butanedioate salts. The separated diastereoisomers were converted into the corresponding optically active arsonium bromides by ion-exchange column chromatography. The absolute configuration of the arsonium cation exhibiting a positive rotation at 589 nm (sodium D line) has been established as (R) by single-crystal X-ray analysis of both the bromide and hexafluorophosphate salts. The arsonium bromide with [α]D + 54.8�(c, 0.62 in CH2Cl2) crystallizes in the orthorhombic space group P212121 (D24, No.19) with a 22.472(8), b 15.724(7), c 12.585(5) � and U 4447(3) �3. The corresponding hexafluorophosphate with [α]D + 19.3� (c, 0.5 in CH2Cl2) crystallizes in the same space group with a 23.56(2), b 16.40(1), c 13.12(1) � and U 5067(6) � 3. Benzylidene transfer to benzaldehyde from the arsonium ylide derived from either of the arsonium salts produced optically pure (–)-(S)-methyl(4-methylphenyl)(naphthalen-1-yl)arsine, [α]D - 115.9� (c, 0.593 in CHCl3), and partly resolved [R-(R*,R*)]-2,3-diphenyloxiran.

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