Richard E. Norman

Di-μ-halo-bis{[tris(2-pyridylmethyl)amine-κ4N]nickel(II)} bis(triethylammonium) tetraperchlorate: Magnetostructural studies

[{Ni(TPA)Br}2](ClO4)2·2HNEt3ClO4, where TPA is tris-(2-pyridylmethyl)amine, crystallizes in the monoclinic space group P21:c with Z2, a11.531(3) A, , b22.141(3) A, , c 12.511(2) A, and b 107.44(1)°. The structure was determined at ambient temperature from 5519 reflections (2937 observed) with R 0.0426 and Rw 0.0404. The [{Ni(TPA)Br}2] 2 core is centrosymmetric with unsymmetrical bridges (NiBr2.504(1) and 2.662(1) A, ). Each Ni atom is pseudo-octahedral six-coordinate. Triethylammonium perchlorate cocrystallizes with the metal complex. Magnetic susceptibility studies (fit to the Ginsberg model) indicate the Ni centers are ferromagnetically coupled with J:k 10.0(5) cm 1 . The chloro complex ([{Ni(TPA)Cl}2](ClO4)2·2HNEt3ClO4) is also ferromagnetically coupled with J:k 7.6(1) cm 1 .

Tri­bromo(3,5-di­methyl-2-nitro­phenyl-κ2C1,O)­tellurium(IV), bromo(3,5-di­methyl-2-nitro­phenyl-κ2C1,O)­tellurium(II) and bromo(3,5-di­methyl-2-nitro­so­phenyl-κ2C1,O)­tellurium(II)

All three title compounds, prepared from bis(3,5-dimethyl-2-nitrophenyl)ditellurium, exhibit high degrees of intramolecular Te-O coordination. Their Te-O distances increase in the order C(8)H(8)BrNOTe < C(8)H(8)BrNO(2)Te < C(8)H(8)Br(3)NO(2)Te, with distances of 2.165 (3), 2.306 (1) and 2.423 (6) A, respectively, indicating that C(8)H(8)BrNOTe may be more aptly described as 1-bromo-4,6-dimethyl-2,1,3-benzoxatellurazole.

Nickel(II) 1,10-Phenanthroline complexes: cis-[Aqua(Bromo) bis (1,10-Phenanthroline)Nickel(II)] Bromide Trihydrate and ( tris (1,10-Phenanthroline)Nickel(II)] Bromide Octahydrate

[Ni(phen)2(H2O)Br]Br·3H2O where phen is 1,10-phenanthroline, is a light-blue material which crystallizes in the monoclinic space group P21/c with Z = 4, a = 10.4300(4), b = 25.310(2), c = 9.7790(9) Å and β = 102.932(6)°. The structure was determined at ambient temperature from 5161 reflections with R = 0.0643 and R w = 0.1306. The structure consists of a complex cation, a bromide anion and three waters of hydration. The Ni atom is pseudo-octahedral with a cis arrangement of Br and H2O. This cis geometry persists in solution, as evidenced by 1H NMR spectroscopy, although the Br may be replaced by another H2O. [Ni(phen)3]Br2·8H2O is a light-red material which crystallizes in the monoclinic space group C2/m with Z = 8, a = 23.6320(11), b = 21.4880(13), c = 15.5470(9) Å and β = 107.927(3)°. The structure was determined at 120 K from 6820 reflections with R = 0.0733 and R w = 0.1022. The structure consists of a complex cation, two bromide anions and eight waters of hydration. The anions and waters are extensively disordered. The Ni atom is pseudo-octahedral.