Renier Koen

Crystal structure of tetraethylammonium hexachloridotantalate(V), C8H20Cl6NTa

Abstract C8H20Cl6N1Ta1, monoclinic, P21/n (no. 14), a = 7.1550(4) Å, b = 10.0090(6) Å, c = 11.6290(4) Å, β = 98.487(5)°, V = 823.7(8) Å3, Z = 2, Rgt(F) = 0.0207, wRref(F2) = 0.0531, T = 100(2) K.

(Acetyl­acetonato-κ2O,O′)chlorido­trimethano­latoniobium(V)

In the title compound, [Nb(CH3O)3(C5H7O2)Cl], the NbV atom is coordinated by two O atoms from the chelating acetylacetonate ligand, three O atoms from the methanolate groups and one chloride ligand. The octahedral environment around niobium is slightly distorted with Nb—O distances in the range 1.8603 (15)–2.1083 (15) Å and an Nb—Cl distance of 2.4693 (9) Å. The O—Nb—O angles vary between 80.74 (6) and 100.82 (7)°, while the trans Cl—Nb—O angle is 167.60 (5)°. There are no hydrogen bonds observed, only an intermolecular C—H⋯O interaction.

Crystal structure of trans-bis((E)-7-oxo-4-(phenyldiazenyl)cyclohepta-1,3,5-trien-1-olato)-κ2O,O′)-bis(pyridine-κN)cobalt(II), C36H28CoN6O4

Abstract C36H28Co1N6O4, triclinic, P1̄ (no. 2), a = 6.3166(4) Å, b = 8.5454(5) Å, c = 14.8075(9) Å, α = 105.157(2)°, β = 94.494(3)°, γ = 101.890(2)°, V = 747.5(2) Å3, Z = 1, Rgt(F) = 0.0332, wRref(F2) = 0.0790, T = 100(2) K.

The crystal structure of 6-chloro-2,4-diphenylquinoline

Abstract C21H14ClN, orthorhombic, Pca21 (No. 29), a = 7.6860(5) Å, b = 10.1610(5) Å, c = 19.8990(5) Å, V = 1554.1(13) Å3, Z = 4, Rgt(F) = 0.0318, wRref(F2) = 0.0783, T = 100(2) K.

An in-depth crystallographic study of tantalum(V) and niobium(V) complexes utilizing various mono- and bidentate ligands

The separation of niobium and tantalum has always been a complicated process, particularly due to their near identical chemical properties. Niobium(V) and tantalum(V) are both hard metal centres and the halido species are known to readily hydrolyse.[1] In this present investigation of tantalum(V) and niobium(V) complexes, different mono-(carbene) and bidentate ligands (L,L’-Bid ) have been used in synthesis, in an attempt to study the variation in activity and selectivity of coordination of L,L’-Bid to tantalum -halides, -methoxides. (L,L’-BidH = acacH, tfaaH, hfaaH and tropH). Different synthetic procedures and characterization methods of these complexes will be discussed. Tantalum(V) and niobium(V) complexes of the type [Ta(X)4(L,L’-Bid)] (X = halides, OMe and OEt; examples of L,L’ = acetylacetonato (acac), dibenzoylmethanato (dbm) and tetramethylheptanedionato (thmd)), were synthesized and characterized by nuclear magnetic resonance spectroscopy (NMR) and infrared (IR).[2] Moreover, single crystal X-ray diffraction was used to evaluate the characteristics of a range of complexes, and the results of the obtained structures containing mono-(halido and pseudo halido) and bidentate hard ligands O,O’-and N,O-donor atoms will be presented and discussed.[3] A kinetic investigation of acacH coordination to solvated TaCl5 is also presented. The reaction is defined by limiting kinetic behaviour and is indicative of a twostep process. This involves the rapid formation of a proposed trans-[TaCl2(OMe)3(η 1 -acacH)intermediate. Comparison of the forward rate constants for the two steps, k1 and k2 indicates that the first reaction is approximately six orders of magnitude (10 6 ) faster than the second slower, rate determining step.

1,1,1,5,5,5-Hexafluoro-2,4-dimeth-oxy-pentane-2,4-diol.

The title compound, C7H10F6O4, was isolated as an unexpected product from a reaction of tantalum(V) methoxide with hexafluoroacetylacetone in a methanol solution. The asymmetric unit consists of one half-molecule with the middle C atom lying on a twofold axis. The crystal structure is stabilized by O—H⋯O and an array of C—H⋯F hydrogen-bonding interactions. These interactions link the molecules into a stable supramolecular three-dimensional network. The molecules pack in a ribbon-like form in the ac plane as a result of these interactions.

trans-Carbonyl­chloridobis(tri-o-tolyl­phosphane-κP)rhodium(I)

In the title compound, [RhCl(C21H21P)2(CO)], the coordination geometry around the RhI atom is slightly distorted square-planar with the phosphane ligands in trans positions with respect to each other. The chloride and carbonyl ligands show positional disorder, and the RhI atom lies on a center of inversion. The effective cone angle ΘE for the title compound is 169.0 (3)°. There are no significant intermolecular interactions.