Tetrahedral molecular geometry

About: Tetrahedral molecular geometry is a research topic. Over the lifetime, 1795 publications have been published within this topic receiving 30706 citations.

The 2-mercapto-1-methylimidazolyl moiety as a bridging ligand in complexes of gallium, rhenium, and molybdenum

Abstract: The synthesis and characterization of complexes containing the 2-mercapto-1-methylimidazolyl ligand are described. occurs as a dimer, crystals of which are monoclinic, C2/c, a = 14.140(2), b = 7.4098(4), c = 18.024(2) A, β = 106.38(1)°, Z = 4 dimers; the structure was determined by conventional heavy atom methods and refined by full-matrix least-squares techniques to a final R value of 0.039 for 1767 reflections. The crystal contains centrosymmetric dimeric molecules, with a central 8-membered ring, formed by mercaptoimidazolyl ligand bridging between dimethylgallium groups; galliumm has tetrahedral geometry, with no tendency to five-coordination, Ga—S = 2.3697(8), Ga—N = 2.019(2) A. Reaction of L−, with [Re(CO)4Cl]2 results in the formation of LRe(CO)3, whose physical properties indicate a fac arrangement of the organogallate ligand. Attempts to synthesize corresponding LMo(η3-C4H7)(CO)2 and LMo(η3-C3H5)(CO)2 complexes yielded the dimeric species and Crystals of the complex are monoclinic, I2/a, a = 15.0...

Copper(I), silver(I) and gold(I) complexes with the hybrid ligand 1-(diphenylphosphino)-2-(2-pyridyl)ethane (ppye). Variable-temperature nuclear magnetic resonance investigations and the crystal structure of [Au(ppye-P)2]PF6

Abstract: Copper(I), silver(I) and gold(I) complexes with the ligand 1-(diphenylphosphino)-2-(2-pyridyl)ethane (ppye) of general formula M(ppye)2PF6 have been prepared and characterized by means of IR and multinuclear (1H, 13C and 31P) NMR spectroscopy. The copper(I) and silver(I) complexes are bis(chelate) with a tetrahedral geometry around the metal atom. On the contrary, the gold(I) derivative exhibits a digonal structure with monodentate P-bound ppye ligands co-ordinated to the metal centre. The complex [Au(ppye-P)2]PF6 has been characterized in the solid state by X-ray diffraction analysis. Crystal data: triclinic, space group P, a= 9.972(1), b= 10.299(2), c= 10.521(2)A, α= 69.90(2), β= 66.03(1), γ= 78.51(1)°, Z= 1, R= 0.039. The gold atom, which lies on a symmetry centre, is linearly co-ordinated by the P atoms of ppye (P–Au–P, 180°). Variable-temperature NMR studies show that the [M(ppye-P,N)2]+ species rearrange in solution by inversion at the tetrahedral metal centre. Furthermore, all three ppye derivatives undergo ligand-exchange processes. The reactions of the cations [M(ppye-P,N)2]+ and [Au(ppye-P)2]+ with ppye have been investigated.

Synthesis and structural characterization of monomeric manganese(II) N-heterocyclic carbene complexes MnX2(C{N(iPr)C(Me)}(2))(2) (X = Cl, I, and MeCOO)

Abstract: Reaction of MnCl2(THF)1.5, MnI2, or Mn(MeCOO)2 with two equivalents of N-heterocyclic carbene [C(Me)N(iPr)]2C (1) in THF at room temperature readily afforded the corresponding carbene adducts [MnX2(C{N(iPr)C(Me)}2)2] [X = Cl (2); X = I (3); X = MeCOO (4)] in good yield. Solid-state structural analysis of complexes 2−4 reveals that all complexes are monomeric. In complexes 2 and 3 the central manganese atoms are four coordinate and have a distorted tetrahedral geometry. The manganese atom in compound 4 has a coordination number of six and resides in a highly distorted octahedral geometry. The N-heterocyclic carbene ligands in these complexes are coordinated differently to the central metal atoms. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)