Margaret E. Kastner

Structural trans effects in some bis(ethylenediamine)cobalt(III) complexes

Abstract The crystal structures of seven bis(ethylenediamine) cobalt(III) complexes with monodentate oxalato, azido, nitro, sulfito and thiosulfato ligands have been determined by single-crystal X-ray diffraction methods. The complexes, space groups, cell constants, number of molecules per unit cell, Z , calculated and experimental densities and final reliability factors are as follows: cis [en 2 Co(NO 2 )- (C 2 O 4 )]·2H 2 O, P 1 , a = 6.925(3), b = 8.055(3), c = 12.158(4)A, α = 80.16(2)°, β = 77.87(2)°, γ= 87.90(2)°, V = 653 A 3 Z = 2, ϱ exp = 1.78 g cm −3 , ϱ calc = 1.76 g cm −3 , R 1 = 5.5, R 2 = 9.4; trans [en 2 - Co(NO 2 )(C 2 O 4 )]·2H 2 O, P 2 1 / n , a = 8.218(2), b = 15.613(1), c = 10.694(1) A, β = 101.49(1)°, V = 1344 A 3 , Z = 4, ϱ exp = 1.73 g cm −3 , ϱ calc = 1.74 g cm −3 , R 1 = 3.5, R 2 = 5.6; cis [en 2 Co(N 3 )(C 2 O 4 )]· H 2 O, P 2 1 / c , a = 8.379(1), b = 15.548(4), c = 9.736(3) A, β = 97.44(2)°, V = 1258 A 3 , Z = 4, ϱ exp = 1.73 g cm −3 ϱ calc = 1.69 g cm −3 , R 1 = 4.3, R 2 = 4.8; trans [en 2 Co(N 3 )(C 2 O 4 )]·2H 2 O, I 4 1 / a , a = 26.684(2), c = 7.625(2) A, V = 5429 A 3 , Z = 16,ϱ exp = 1.69 g cm −3 , ϱ calc = 1.69 g cm −3 , R 1 = 6.6, R 2 = 7.9; cis -NH 4 [en 2 Co(S 2 O 3 )(SO 3 )]·3H 2 O, P 2 1 / n , a = 10.094(9), b = 12.205(12), c = 13.358(3) A, β = 90.19(4)°, V = 1646 A 3 , Z = 4, ϱ exp = 1.79 g cm −3 , ϱ calc = 1.78 g cm −3 , R 1 = 7.6, R 2 = 9.2; cis [en 2 - Co(N 3 )(SO 3 )]·1.5H 2 O, P 2 1 / n , a = 7.749(1), b = 10.701(2), c = 15.101(4) A, β = 102.80(2)°, V = 1221 A 3 , Z = 4, ϱ exp = 1.78 g cm −3 , ϱ calc = 1.78 g cm −3 , R 1 = 3.2, R 2 = 4.0; cis [en 2 Co(NO 2 )(SO 3 )]· 1H 2 O, P 2 1 / c , a = 6.629(2), b = 11.429(4), c = 15.156(4) A, β = 93.27(2)°, V = 1146 A 3 , Z = 4, ϱ exp = 1.87 g cm −3 , ϱ calc = 1.86 g cm −3 , R 1 = 3.5, R 2 = 4.4. Additionally, the previously reported structure of cis [en 2 Co(N 3 ) 2 ]NO 3 has been redetermined: Pnma , a =11.903(3), b =23.566(6), c = 8.877(2) A, V = 2493 A 3 , Z = 8, ϱ exp = 1.73 g cm −3 , ϱ calc = 1.73 g cm −3 , R 1 = 4.8, R 2 = 5.9. The structural trans effect, STE , the difference between the CoN(en) bond length trans to a ligand and the average of the two CoN(en) bond lengths that are both cis to that ligand and trans to each other, decreases in the series SO 3 2− [0.059(7) A]> SSO 3 2− [0.036(9) A]> NO 2 − [0.019 (10) A]> N 3 − [0.005(6) A]> C 2 O 4 2− [0.000(6) A].

Caging the mercurous ion: a tetradentate tripodal nitrogen ligand enhances stability and J(1H199Hg)

AbstractThe dimeric mercurous ion has been encapsulated by a pair of the tetradentate tripodal nitrogen ligands tris[(2-(6-methylpyridyl))methyl]amine (TLA). The complex [Hg2(TLA)2](ClO4)2 (1) was isolated directly from an acetonitrile solution of Hg(ClO4)2 ⋅ 3H2O and TLA. Complex 1 crystallizes in the triclinic space group

Redetermination of cis-diaqua­diglycolato­zinc(II)

\bar P1

A 3,5-dinitro­benzoyl derivative of a stereoisomer of glycerol menthonide

with a = 10.537(2) Å, b = 10.751(2) Å, c = 10.907(2) Å, α = 75.20(3)○, β = 73.73(3)○, γ = 75.73(3)○, and Z = 1. The cation is located an inversion center. The Hg–Hg and Hg–Namine bond distances are 2.5469(8) and 2.297(6) Å, respectively, and the average Hg–Npyridyl bond length is 2.75(7) Å. Complex 1 was stable indefinitely in acetonitrile-d3 solution, permitting detection of 13 and 22 Hz heteronuclear couplings between the Hg(I) ions and the methylene protons of the ligand. Comparisons with the structures and spectroscopic properties of related mercuric and mercurous complexes are made.

2-(1,2,3,4-Tetra-hydro-phenanthren-1-yl-idene)malononitrile.

Crystals of the title compound, [Co(NH(3))(6)][Gd(C(6)H(6)NO(6))(2)(H(2)O)].8H(2)O, were synthesized in and collected from aqueous solution. The hexaamminecobalt(III) cation has the expected octahedral geometry, while the Gd coordination sphere has the geometry of a tricapped trigonal prism, with the two nitrilotriacetate N atoms and one water molecule occupying the capping positions.

5a-Butyl-1,3,8,10-tetra-chloro-7,13-bis-(4-nitro-benzo-yl)-5a,6a,12a,12b-tetra-hydro-7H,13H-thieno[2,3-b:4,5-b']bis-(1,4-benzoxazine).

The title complex, [Zn(C2H3O3)2(H2O)2], was prepared and the crystal structure determined as part of a 67Zn solid state nuclear magnetic resonance study. In the title complex, the Zn atom has a disorted octahedral coordination comprising two bidentate glycolate ligands and two water molecules. The water molecules are cis to each other; one is trans to a carboxylate O atom and the other trans to an alcohol O atom. The crystal structure has an extensive O—H⋯O hydrogen-bond network.

4-Bromo-2H-1,3-oxazine-2,6(3H)-dione.

Abstract The structures of two derivatives of Ni(II) containing 2-acetylpyrrole are reported. The first compound is a dimer containing four 2-acetylpyrrole and two isopropylamine molecules, with the nickel centers bridged by carbonyl oxygen atoms from two of the four 2-acetylpyrrole groups. The second derivative is a monomer containing two n-butylamine and two 2-acetylpyrrole molecules, with the latter arranged in a planar fashion around the nickel center. Crystals of the dimer are triclinic with space group P 1 with a=8.281(2), b=9.694(2), c=11.495(2) A, α=110.08(3), β=105.57(3), γ=99.35(3)°, V=801.1(2) A3 and Z=1. Crystals of the monomer are triclinic with space group P 1 with a = 5.626(2), b = 9.803(2), c = 10.792(2) A, α = 74.96(2), β = 81.81(2), γ=83.34(2)°, V=566.9(2) A3 and Z=1.

4-Methyl-2H-1,3-oxazine-2,6(3H)-dione.

The title compound, [(2S,5R,6S,9R)-6-isopropyl-9-methyl-1,4-dioxaspiro[4.5]dec-2-yl]methyl 3,5-dinitrobenzoate, C20H26N2O8, was synthesized as part of a study of three-carbon stereochemical systems. The crystallographic assignment of the absolute stereochemistry is consistent with having started with (−)-menthone, the acetal carbon is R and the secondary alcohol is S. This brings the dinitrobenzoate into approximately the same plane as the menthyl ring and anti to the isopropyl group. Close intermolecular C=O⋯NO2 contacts between neighboring molecules [2.8341 (16) Å] contribute to the packing arrangement. The structure was refined as a pseudo-merohedral twin (monoclinic space group P21 emulating the orthorhombic space group C2221). Application of the twin law 100, 00, 0 gave a 2:1 ratio of twin moieties [refined BASF value = 0.3790 (7)].