ChemInform Abstract: Crystal and Molecular Structure Determination of Tetraethyl-Ammonium Triiodomercurate(II), (C2H5)4NHgI3.

A low-temperature single-crystal X-ray structure determination of the 1 : 1 adduct of copper(II) nitrate with 2,2′-diphenyl-4,4′-bithiazole (L) shows it to be a molecular complex with L behaving as a symmetrical N,N′ chelate, and the nitrate groups as unsymmetrical O,O′ chelates: [LCu(O2NO)2]. Two polymorphs, both monoclinic P21/c, have been obtained from acetonitrile (‘α’) and methanol (‘β’), respectively, with one molecule, devoid of crystallographic symmetry, in the asymmetric unit of each structure. The copper environments are distorted planar four-coordinate, cis-N2CuO2 (Cu–N 2.011(1), 1.973(1), Cu–O 1.995(1), 1.962(1) Å), ‘in-plane’ angle sum Σ 369.5°, with longer trans, axial contacts (Cu–O 2.455(1), 2.458(2) Å) for the α-form; respective values are 1.995(5), 1.991(4), 1.997(4), 1.973(3) Å, 360.4°, 2.500(4), and 2.396(4) Å for the β-form.

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Complexes of the methyl tris(3,5-dimethylpyrazol-1-yl) gallate ligand, MeGa(N2C5H7)3−, and its hydroxy derivative, MeGa(N2C5H7)2(OH)−. Crystal and molecular structure of [MeGa(N2C5H7)2(OH)]Mo(CO)2(η3-C4H7)

Canadian Journal of Chemistry ◽

10.1139/v79-023 ◽

1979 ◽

Vol 57 (2) ◽

pp. 139-146 ◽

Cited By ~ 18

Author(s):

Kenneth R. Breakell ◽

Steven J. Rettig ◽

Alan Storr ◽

James Trotter

Keyword(s):

Molecular Structure ◽

Crystal Structure ◽

Least Squares ◽

Structure Determination ◽

Carbonyl Compounds ◽

Crystal And Molecular Structure ◽

Hydroxy Derivative ◽

Full Matrix ◽

Sterically Demanding

The synthesis and coordinating properties of the tridentate tris-chelating ligand, methyl tris(3,5-dimethylpyrazol-1-yl)gallate, MeGa(N2C5H7)3−, are described. Carbonyl and nitrosyl carbonyl compounds of manganese, molybdenum, and tungsten incorporating this ligand are detailed. The ready conversion of the above ligand to the less sterically demanding tris-chelating 'hydroxy' ligand [MeGa(N2C5H7)2(OH)]− occurs in attempted syntheses of the 'η3-allyl' complexes, [MeGa(N2C5H7)3]M(CO)2'η3-allyl', (where M = Mo or W, 'η3-allyl' = η3-C3H5, η3-C4H7). The tridentate chelating nature of this 'hydroxy' ligand is conclusively demonstrated in the crystal structure determination of the complex, [MeGa(N2C5H7)2(OH)]-Mo(CO)2(η3-C4H7). Crystals of this complex are monoclinic, a = 14.020(4), b = 10.110(1), c = 15.493(7) Å, β = 111.58(3)°, Z = 4, space group P21/n. The structure was solved by Patterson and Fourier syntheses and was refined by full-matrix least-squares procedures to a final R of 0.40 and Rw of 0.043 for 3374 reflections with I ≥ 3.5σ(I).

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Crystal and Molecular Structure of 4-Arylhexahydro-1H,3H-pyrido[1,2-c]pyrimidine-1,3-dione Derivatives

Zeitschrift für Naturforschung B ◽

10.1515/znb-2002-1118 ◽

2002 ◽

Vol 57 (11) ◽

pp. 1315-1319 ◽

Cited By ~ 3

Author(s):

Irena Wolska ◽

Franciszek Herold

Keyword(s):

Molecular Structure ◽

Crystal Structure ◽

Hydrogen Bonds ◽

Structure Determination ◽

Phenyl Ring ◽

Crystal And Molecular Structure ◽

X Ray ◽

Saturated Ring ◽

Centrosymmetric Dimers

The X-ray crystal structure determination of 4-(2-methylphenyl)hexahydro-1H,3H-pyrido[ 1,2-c]pyrimidine-1,3-dione (2) and 4-(3-methylphenyl)hexahydro-1H,3H-pyrido[1,2-c]- pyrimidine-1,3-dione (3) is reported. The crystal structures show the formation of centrosymmetric dimers via intermolecular N-H···O hydrogen bonds. The saturated ring adopts a slightly distorted halfchair conformation in both 2 and 3. In either compound the planar phenyl ring is twisted with respect to the pyrimidine-1,3-dione fragment.

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