The synthesis and structural characterization of a series of pentacoordinate diorganotin(IV) N-arylidene-α-amino acid complexes

1992 ◽  
Vol 70 (4) ◽  
pp. 1114-1120 ◽  
Author(s):  
F. E. Smith ◽  
Rosemary C. Hynes ◽  
T. T. Ang ◽  
L. E. Khoo ◽  
G. Eng

Eight new diorganotin complexes formulated as R2Sn(OArCR″=NCHR′COO) were prepared and characterized by 1H and 13 C NMR, IR, and elemental analysis. A single crystal X-ray diffraction study of the dibutyltin N-salicylidenevaline complex, Bu2Sn(OC6H4CH=NCH(i-Pr)COO), determines the molecular structure. The crystals are orthorhombic, space group P212121 with a = 9.187(2) Å, b = 10.003(2) Å, c = 23.482(4) Å, V = 2157.8(6) Å3, Z = 4, and Dc = 1.392 g cm−3. The final discrepancy factors are RF = 0.040, and Rw = 0.021 for 1131 significant reflections. The tin atom has a distorted trigonal bipyramidal coordination, with no short intermolecular contacts. The two axial Sn—O bonds of 2.078(10) and 2.151(8) Å and the equatorial Sn—N bond of 2.158(8) Å are among the shortest found in related complexes. The fact that the closest intermolecular Sn—O distance is 4.511(8) Å indicates a nonbridging carbonyl group.

1996 ◽  
Vol 74 (11) ◽  
pp. 2041-2047 ◽  
Author(s):  
Frank. E. Smith ◽  
Lian Ee Khoo ◽  
Ngoh Khang Goh ◽  
Rosemary C. Hynes ◽  
George Eng

The new diorganotin complex ((C6H5)2Sn(OC10H6CH=NCH2COO)) was prepared and characterized by 1H NMR, IR, elemental analysis, and a single crystal X-ray diffraction study. The crystals are monoclinic, space group P21/a with a = 16.9167(9) Å, b = 19.1276(16) Å, c = 26.538(2) Å, β = 100.534(6)°, V = 8442.5(11) Å3, Z = 16, and Dcalc = 1.574 Mg m−3. The final discrepancy factors are RF = 0.030, and RW = 0.021 for 6524 significant reflections. The tin atom has a distorted trigonal bipyramidal coordination, with no short intermolecular contacts. The two axial Sn—O bonds of 2.12 Å and 2.09 Å and the equatorial Sn—N bond of 2.14 Å are among the shortest found in related complexes. Key words: diorganotin(IV), bicycloazastannoxide, trigonal bipyramidal, antitumour.


2006 ◽  
Vol 61 (5) ◽  
pp. 555-559 ◽  
Author(s):  
Veysel T. Yilmaz ◽  
Vecdi Kars ◽  
Canan Kazak

The new cadmium and mercury saccharinate (sac) complexes, cis-[Cd(sac)2(dmea)2] (1) and [Hg(sac)2(dmea)(H2O)] (2) (dmea = 2-dimethylaminoethanol), have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. In complex 1, the cadmium(II) ion is coordinated by two neutral dmea ligands and two sac anions in a distorted octahedral CdN3O3 coordination geometry. The dmea ligand acts as a bidentate N, O chelate, while the sac ligands behave as an ambidentate ligands. One of them coordinates to the cadmium(II) ion through the carbonyl oxygen atom, while the other is N-bonded. In complex 2, the mercury(II) ion is coordinated by an aqua ligand, a chelating dmea ligand and two N-bonded sac ligands, forming a distorted trigonal bipyramidal coordination HgN3O2. The molecules interact with each other through O-H···O hydrogen bonds and aromatic π(sac)···π(sac) stacking interactions, leading to a three-dimensional supramolecular network.


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.


1980 ◽  
Vol 58 (8) ◽  
pp. 777-779 ◽  
Author(s):  
T. Stanley Cameron ◽  
Christine Chan ◽  
David G. Morris ◽  
Alistair G. Shepherd

The crystals belong to the orthorhombic space group C222, with a = 9.226, b = 12.092, c = 16.513 Å, Z = 4. A single crystal X-ray diffraction analysis has shown that the title compound, in which all carbon atoms are sp2 hybridized, exists with the ten membered ring in a slightly twisted tub conformation. The 13C nmr spectrum is also reported.


2020 ◽  
Vol 44 (11-12) ◽  
pp. 721-726
Author(s):  
Xiaolong Wang ◽  
Xian Yue ◽  
Long Deng

Two novel mononuclear Zn(II) complexes, [ZnL1Cl2] (1) (L1=( E)-3-(4-(2,2′:6′,2″-tripyridyl)-4′-styryl)-7-diethylaminocoumarin) and [ZnL2Cl2] (2) (L2=3-(4-(2,2′:6′,2″-tripyridyl)-4′-phenylimine)-7-diethylaminocoumarin), were obtained by the solvothermal method from ZnCl2 and coumarin-based terpyridine ligands. The complexes were characterized by spectroscopic methods and single-crystal X-ray diffraction. The Zn2+ in the complexes is coordinated by three nitrogen atoms of the terpyridine ligand and two chloride anions, forming a distorted trigonal bipyramidal environment. Moreover, the UV–Vis absorption and emission spectra of the ligands and complexes in diluted dichloromethane solutions were measured.


2014 ◽  
Vol 69 (6) ◽  
pp. 737-741 ◽  
Author(s):  
Gustavo A. Echeverría ◽  
Oscar E. Piro ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran

Ammonium acesulfamate, (NH4)C4H4NO4S, was prepared by the reaction of acesulfamic acid and ammonium carbonate in aqueous solution, and characterized by elemental analysis and 1H and 13C NMR spectroscopy. Its crystal and molecular structure was determined by single-crystal X-ray diffraction methods. The substance crystallizes in the orthorhombic space group Pnma with Z = 4 molecules per unit cell. The NH4+ ion generates medium to strong hydrogen bonds with the carbonylic oxygen, the iminic nitrogen and the sulfonyl oxygen atoms of the acesulfamate anion. The FTIR spectrum of the compound was also recorded and is briefly discussed.


2020 ◽  
Vol 12 (4) ◽  
pp. 51-62
Author(s):  
A. Efremov ◽  

Tetraphenylantimony 2,3-difluorobenzoate (1) and tetraphenylantimony 2,3,4,5,6-pentafluorobenzoate (2) was obtained by the interaction of pentaphenylantimony with 2,3-difluorobenzoic and 2,3,4,5,6-pentafluorobenzoic acids in benzene with a yield of up to 98 %. The compounds were also synthesized by the ligand redistribution reaction between pentaphenylantimony and triphenylantimony dicarboxylates. The compounds have been identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray diffraction data, the antimony atoms in compounds 1 and 2 have a distorted trigonal-bipyramidal coordination with the oxygen atom in axial positions. X-ray diffraction analysis was performed on a D8 QUEST diffractometer (Bruker). The crystallographic parameters of the unit cell of the compounds: 1 space group Р1 ̅, а = 9.857(5), b = 10.154(7), c = 14.362(11) Å, α = 83.74(4)°, β = 82.59(3), γ = 68.34(2)°, V = 1321.9(16) Å3, ρcalc = 1.475 g/cm3, Z = 2; 2 space group Р21/с, а = 16.186(9), b = 8.771(6), c = 20.413(13) Å, α = 90.00°, β = 113.073(17), γ = 90.00°, V = 2666(3) Å3, ρcalc = 1.597 g/cm3, Z = 4. The OSbO axial angles are slightly different and amount to 177.90(5)º in 1 and 179.00(5)º in 2. The sums of the CSbC equatorial angles are 356.89(9)º (1), 355.85(7)º (2). The Sb–Ceq distances in compounds 1 and 2 are 2.116(2), 2.119(2), 2.118(2) and 2.1073(17), 2.1158(18), 2.1152(19) Å respectively, which are significantly shorter than the Sb–Сax bond lengths (2.169(2) and 2.1617(19) Å). The organization of molecules in the crystals of compounds is due to hydrogen bonds and CHπ-interactions of the aryl and carboxyl ligands. The main difference between structures 1 and 2 is the different Sb–O bond lengths (2.2864(18) and 2.3168(18) Å), which is due to an increase in the electronegativity of the carboxyl ligand in 2, caused by the presence of five electronegative fluorine atoms in the benzoate substituent. Complete tables of atom coordinates, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Center (No. 1980908 (1); 1977189 (2); [email protected]; http://www.ccdc.cam.ac.uk/data_request/cif).


1984 ◽  
Vol 62 (3) ◽  
pp. 601-605 ◽  
Author(s):  
Masood A. Khan ◽  
Clovis Peppe ◽  
Dennis G. Tuck

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.


Author(s):  
Michael R. Jackson ◽  
Thomas L. Selby

A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) fromStreptomyces antibioticushas been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space groupP222, with unit-cell parametersa= 41.26,b= 51.86,c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution.


Author(s):  
Stephanie J. Hong ◽  
Jun Li ◽  
Mas A. Subramanian

The crystal structure of magnesium zinc divanadate, MgZnV2O7, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with Mn0.6Zn1.4V2O7 (C2/m; Z = 6) and is related to the crystal structure of thortveitite. The asymmetric unit contains two metal sites with statistically distributed magnesium and zinc atoms with the atomic ratio close to 1:1. One (Mg/Zn) metal site (M1) is located on Wyckoff position 8j and the other (M2) on 4h. Three V sites (all on 4i), and eight O (three 8j, four 4i, and one 2b) sites complete the asymmetric unit. The structure is an alternate stacking of V2O7 layers and (Mg/Zn) atom layers along [20\overline{1}]. It is distinct from other related structures in that each V2O7 layer consists of two groups: a V2O7 dimer and a V4O14 tetramer. Mixed-occupied M1 and M2 are coordinated by oxygen atoms in distorted trigonal bipyramidal and octahedral sites, respectively.


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