An unusual trigonal-bipyramidal coordination of aluminum by an open-chain tetradentate amine. Synthesis and molecular structure of [Al(CH3)][C8H19N4][Al(CH3)2]

1988 ◽  
Vol 7 (8) ◽  
pp. 1887-1889 ◽  
Author(s):  
Gregory H. Robinson ◽  
Samuel A. Sangokoya ◽  
Fritz. Moise ◽  
William T. Pennington
Keyword(s):  
Molecular Structure ◽  
Open Chain ◽  
Trigonal Bipyramidal Coordination ◽  
Trigonal Bipyramidal

Synthesis, Structures and Reactions of Trimethyltantalum(V) Bis[tri(tert.-butyl)silanolate]

2011 ◽  
Vol 66 (4) ◽  
pp. 392-396
Author(s):  
Jörg Knizek ◽  
Heinrich Nöth
Keyword(s):  
Molecular Structure ◽  
Equatorial Plane ◽  
Tert Butyl ◽  
Trigonal Bipyramidal Coordination ◽  
Trigonal Bipyramidal

Bis[tri(tert.-butyl)silanolato]tantalum(V) trichloride reacts with LiMe to give trimethyl-bis[tri- (tert.-butyl)silanolato]tantalum(V), 6. Its molecular structure shows a trigonal-bipyramidal coordination of the Ta atom with the Me groups in the equatorial plane. Its reaction with catecholborane produces preferably B-methyl-catecholborane besides some phenylene-1,2-dioxo-bis(1,3,2-dioxaborolane), 9, and H3 B・ THF. Similarly, the reaction of 6 with dimeric 9-borabicyclononane (9-BBN) generates preferable tri(tert.-butyl)siloxy-9-BBN (75%) and Me-9-BBN (25%). In contrast, cleavage of the Ta-O bonds is the preferred route in the treatment of 6 with H3B ・ THF. 11B NMR shows the formation of (tBu3SiO)2BH and (tBu3SiO)3B or (tBuSiO)3B3O3. No tantalum hydride could be isolated.

On the structural diversity anions coordinate to the butterfly-shaped [(R2Sn)3O(OH)2]2+ cations and vice versa

2014 ◽  
Vol 92 (6) ◽  
pp. 496-507 ◽  
Author(s):  
Hans Reuter ◽  
Hilko Wilberts
Keyword(s):  
Hydrogen Bonds ◽  
Iodine Atom ◽  
Structural Parameters ◽  
Structural Diversity ◽  
Hydroxyl Groups ◽  
Equatorial Position ◽  
Chelating Ligands ◽  
Trigonal Bipyramidal Coordination ◽  
Trigonal Bipyramidal ◽  
Oxygen Framework

The syntheses and crystal structures of [(t-Bu2Sn)3O(OH)2]CO3·3MeOH, 1a, [(t-Bu2Sn)3O(OH)2]CO3·3H2O·acetone, 1b, [(t-Bu2Sn)3O(OH)2][I]2·[(t-Bu2Sn(OH)I]2·2DMSO, 1c, and [(Cy2Sn)3O(OH)2][I]2·2DMSO, 2a, all containing the trinuclear [(R2Sn)3O(OH)2]2+ ion have been described. The butterfly shape of this cation is derived from two annulated, four-membered tin–oxygen rings with a central μ3-oxygen atom and trigonal-bipyramidally coordinated tin atom both belonging to both rings and two μ2-hydroxyl groups and two outer, four-fold coordinated tin atoms. In 1a and 1b, the carbonate anions interact with the outer tin atoms of the cations as bidentate chelating ligands in the classical syn–syn coordination mode, and vice versa. In this way, both outer tin atoms expand their coordination sphere from four to five, with the consequence that bond angles and lengths within the cation are determined by the axial and equatorial position of the oxygen atoms within the trigonal-bipyramidal coordination on all three tin atoms. 1c consists of two different building units, an up to now unknown hydroxide iodide of composition [(t-Bu2Sn(OH)I]2 with hydrogen-bonded DMSO molecules and a [(t-Bu2Sn)3O(OH)2]2+ cation with one coordinated and one isolated, via hydrogen bonds connected iodine ion. The hydroxide iodine is built up of two five-fold coordinated tin atoms linked via two hydroxyl groups with exocyclic iodine atoms occupying axial positions at the trigonal-biypramidally coordinated tin atoms. The unprecedented coordination of the iodine ion to the [(t-Bu2Sn)3O(OH)2]2+ cation takes place between both outer tin atoms, resulting in a five-fold, trigonal-bipyramidal coordination at these tin atoms, too. Structural parameters within the so-formed [(t-Bu2Sn)3O(OH)2I]+ complex are very similar to those of 1a and 1b, with the exception of a significant lengthening of the tin–oxygen bonds opposite to the bridging iodine atom. 2a represents the first example of the [(R2Sn)3O(OH)2]2+ cation without R = t-butyl, so far. In the solid, it consists of two crystallographic independent [(Cy2Sn)3O(OH)2][I]2 building units, each connected to two DMSO molecules via hydrogen bonds. Both building units are very similar with respect to their conformation. Each of the iodine anions coordinates with only one of the two outer tin atoms, one in an inwards, one in an outwards to the tin-oxygen framework directed position. These tin atoms are therefore also trigonal-bipyramidally coordinated as in 1a−1c, but because of steric reasons one of the trigonal-bipyramids has changed its orientation within the tin–oxygen framework, accompanied by enormous changes of bond lengths and angles therein.

scholarly journals The crystal and molecular structure of the bis(N,N,N′,N′-tetramethylethanediamine) adduct of I(Br)InInBr2, In2Br3I•2C6H16N2, an indium–indium bonded molecule

1984 ◽  
Vol 62 (3) ◽  
pp. 601-605 ◽  
Author(s):  
Masood A. Khan ◽  
Clovis Peppe ◽  
Dennis G. Tuck
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Orthorhombic Space Group ◽  
Trigonal Bipyramidal ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Heavy Atom Method ◽  
Distorted Trigonal Bipyramidal

The crystal structure of the title compound has been determined by the heavy atom method. The crystals are orthorhombic, space group Pbca, with unit cell dimensions a = 22.795(3) Å, b = 17.518(2) Å, c = 12.396(3) Å, Z = 8; R = 0.0409 for 1527 unique "observed" reflections. The structure is disordered, with each halogen site (X) occupied by 75% Br, 25% I. The molecule consists of two X2(tmen)In units (tmen = N,N,N′,N′-tetramethylethanediamine) with distorted trigonal bipyramidal geometry, joined by an In—In bond 2.775(2) Å in length.

Crystal and molecular structure of diorganoammonium oxalatotrimethylstannate, [R2NH2][Me3Sn(C2O4)] (R=i-Bu, cyclohexyl)

2011 ◽  
Vol 34 (5-6) ◽  
pp. 127-130 ◽  
Author(s):  
Yaya Sow ◽  
Libasse Diop ◽  
Kieran C. Molloy ◽  
Gabrielle Kociok-Köhn
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonds ◽  
Diffraction Study ◽  
Crystal And Molecular Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Trans Complex ◽  
A Chain ◽  
Distorted Trigonal Bipyramidal

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.

Isopropyl N-Arylmalonamates. Synthesis, Structure, Conformation and Reactions with Carbon Disulfide

2006 ◽  
Vol 71 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Wolf-Dieter Rudorf ◽  
Dušan Loos ◽  
Joanna Wybraniec ◽  
Naďa Prónayová ◽  
Ryszard Gawinecki ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Hydrogen Bonding ◽  
Carbon Disulfide ◽  
Aromatic Amines ◽  
Alkylating Agent ◽  
Sodium Hydride ◽  
Open Chain ◽  
Ketene Dithioacetals ◽  
Correlation Analyses ◽  
C Nmr

Acylation of aromatic amines 1 with diisopropyl malonate (2) leads to a mixture of isopropyl N-arylmalonamates 3 and malonanilides 4. The reaction of 3 with carbon disulfide in the presence of sodium hydride gives disodium salts 5. Treatment of 5 with an alkylating agent yields the open-chain or cyclic ketene dithioacetals 6, 7 or 8. The molecular structure, hydrogen bonding and preferential conformation of the isopropyl N-arylmalonamates 3, 6 and 7 were investigated using correlation analyses of IR, 13C NMR and AM1 semiempirical data.

scholarly journals catena-Poly[[aqualithium(I)]-μ-3-carboxy-5,6-dimethylpyrazine-2-carboxylato-κ4O2,N1:O3,N4]

2013 ◽  
Vol 69 (12) ◽  
pp. m655-m656
Author(s):  
Wojciech Starosta ◽  
Janusz Leciejewicz
Keyword(s):  
Rotation Axis ◽  
Three Dimensional ◽  
Acid Group ◽  
Water Molecules ◽  
Carboxylic Acid Group ◽  
Trigonal Bipyramidal Coordination ◽  
Trigonal Bipyramidal ◽  
Carboxylate Anions ◽  
Group Form ◽  
Intramolecular Hydrogen

The asymmetric unit of the title compound, [Li(C8H6N2O4)(H2O)]n, comprises three Li cations, two of which are located on a twofold rotation axis, two carboxylate anions and three water molecules, of which two are situated on the twofold rotation axis being aqua ligands. Both carboxylate anions are in μ2-bridging mode. All Li ions show a trigonal–bipyramidal coordination mode; the two located in special positions are bridged throughN,O-bonding sites generating a polymeric ribbon along thec-axis direction. The Li cation in a general position creates an independent polymeric ribbon throughN,O-bonding sites of the two symmetry-related ligands; the trigonal–bipyramidal coordination is completed by an aqua ligand. In both carboxylate anions, a carboxylate and a carboxylic acid group form an intramolecular hydrogen bond. The polymeric ribbons running along [001] are interconnected by hydrogen bonds in which the water molecules act as donors and carboxylate O atoms act as acceptors, giving rise to a three-dimensional architecture.

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