Marietjie Schutte-Smith

Distorted octahedral environments in tricarbonylrhenium(I) complexes of 5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olate and 5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olate.

The Re(I) centres of two Re(I)-tricarbonyl complexes, viz. tricarbonyl(pyridine-κN){5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olato-κ(2)N(1),O}rhenium(I), [Re(C23H21N4O)(CO)3], (I), and {5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olato-κ(2)N(1),O}tricarbonyl(pyridine-κN)rhenium(I), [Re(C28H23N6O)(CO)3], (II), are facially surrounded by three carbonyl ligands, a pyridine ligand and either a 5-[2-(2,4,6-trimethylphenyl)diazen-1-yl]quinolin-8-olate [in (I)] or a 5,7-bis[2-(2-methylphenyl)diazen-1-yl]quinolin-8-olate [in (II)] ligand, in a slightly distorted octahedral environment. The crystal structure of (I) is stabilized by two intermolecular C-H···O interactions and that of (II) is stabilized by three intermolecular C-H···O hydrogen-bonding interactions.

Crystal structure of fac-(acetylacetonato-κ2O,O′)tricarbonyl(tri(p-tolyl)phosphine-κP)rhenium(I), C29H28O5PRe

Abstract C29H28O5PRe, triclinic, P1̄ (no. 2), a = 12.733(7) Å, b = 18.668(11) Å, c = 24.779(15) Å, α = 101.442(20)°, β = 100.844(18)°, γ = 104.240(19)°, V = 5419(9) Å3, Z = 8, Rgt(F) = 0.0307, wRref(F2) = 0.0772, T = 100 K.

Pyrones and related ligand analogues in applied inorganic chemistry

The commercially available pyrones: 3-hydroxy-2-methylpyran-4-one (1) and 3-hydroxy-2-ethylpyran-4-one (2) were functionalised to yield the respective 3-hydroxy-2-methylpyrid-4-one (3) and 3-hydroxy-2-ethylpyrid-4-one (4) derivatives. These ligands were then coordinated to an array of metals to form the corresponding complexes. A total of eight bidentate ligands were used in this study with different electronic and steric demands. These ligands are explored for: (i) the potential beneficiation of Hafnium and Zirconium for the nuclear industry, (ii) application as model complexes for diagnostic and therapeutic radiopharmaceuticals in studies using the fac-ReI(CO)3+ core and (iii) exploiting as model Rhodium(I) homogeneous catalysts.[2][3]

Crystal structure of tetraethylammonium 3,5-dinitrosalicylate, C15H23N3O7

Abstract C7H3N2O7, C8H20N, monoclinic, P21/n, a = 11.477(3) Å, b = 6.858(1) Å, c = 21.254(5) Å, β = 92.96(1)°, V = 1670.6(9) Å3, Z = 4, Rgt(F) = 0.0432, wRref(F2) = 0.1279, T = 100(2) K.

Crystal structure of hexacarbonyl bis(μ2-2-methoxybenzenethiolato-κ2S)pyridine(triphenylphosphane)dirhenium(I), C43H34NO8PS2Re2

Abstract C43H34NO8PS2Re2, monoclinic, P21/c (no. 14), a = 12.165(8) Å, b = 19.027(11) Å, c = 18.848(14) Å, β = 108.735(2)°, V = 4131(5) Å3, Z = 4, Rgt(F) = 0.0308, wRref(F2) = 0.0683, T = 100(2) K.

Crystal structure of fac-hexacarbonylbisμ2-(3-carboxy-3′-carboxylato-2,2′-bipyridine)-κ3N,N′:O-dirhenium(I) tetrahydrate, C30H22N4O18Re2

Abstract C30H22N4O18Re2, monoclinic, P21/c (no. 14), a = 10.167(7) Å, b = 17.57(1) Å, c = 19.95(1) Å, β = 98.75(1)°, V = 3522(9) Å3, Z = 4, Rgt(F) = 0.0275, wRref(F2) = 0.0633, T = 100(2) K.

Crystal structure of 3,5,7-tris(morpholinomethyl)tropolone·0.67 hydrate, C22H33N3O5·0.67H2O

Abstract C22H33N3O5·0.67H2O, monoclinic, P21/c, a = 11.9915(6) Å, b = 18.9934(10) Å, c = 10.5332(5) Å, β = 112.155(2)°, V = 2221.91(19) Å3, Z = 4, Rgt(F) = 0.0417, wRref(F2) = 0.1139, T = 100(2) K.

Crystal structure of tetraethylammonium fac-tricarbonyl(hexafluoroacetylacetonato-κ2O,O′)-(nitrato-κO)rhenium(I), C16H21O8N2F6Re

Abstract C16H21O8N2F6Re, triclinic, P1̅, a = 9.161(5) Å, b = 10.283(5) Å, c = 12.974(5) Å, α = 87.739(5)°, β = 78.339(5)°, γ = 75.047(5)°, V = 1156.3(10) Å3, Z = 2, Rgt(F) = 0.037, wRref(F2) = 0.1012, T = 100(2) K.

Solution and solid state effects of coordinated ligands in rhenium (I) complexes

In the last few years the coordination chemistry of rhenium and technetium has gained major interest for the possible use in radiopharmacy, due to its compact size, its low positive charge, coordination properties, d6 low-spin configuration and significant stability. This interest was further fuelled when Alberto remarkably synthesized fac-[99mTc-(CO)3(H2O)3] from [99mTcO4]in aqueous medium and under mild conditions. Several fac-[M(CO)3]+ (M = Re, 99mTc) type complexes have been synthesized to date with a large number of ligand systems.[1,2] The three labile aqua ligands on the starting synthon fac-[Re(CO)3(H2O)3]+ can easily be substituted by a variety and/or combinations of ligands producing stable compounds and potential radiopharmaceuticals with many different characteristics. Our interest focuses on the fac-[Re(CO)3]+ moiety and related compounds by adopting the [2+1] approach.[3] The solid state behaviour of the complexes are explored as well as different effects such as the charge of the complexes as well as the effect of different types of donor atoms and electron donating or withdrawing systems. The influence of coordinated bidentate ligands on the rate of substitution in solution, by a variety of entering ligands, is also investigated. Crystal structures of Re(I) tricarbonyl tropolonato complexes with various monodentate incoming ligands were obtained in the study and will form part of this presentation.