Coulombic inter-ligand repulsion effects on the Pt(II) coordination chemistry of oligocationic, ammonium-functionalized triarylphosphines.

The Pt(II) coordination chemistry of oligocationic ammoniomethyl- and neutral aminomethyl-substituted triarylphosphines (L) is described. Complexes of the type PtX(2)(L)(2) (X = Cl, I) have been isolated and characterized. For the hexa-meta-ammoniomethyl-substituted ligands [1](6+) and [2](6+), two ligands always occupy a trans-configuration with respect to each other in complexes of the type PtX(2)(L)(2), while for the tri-para-ammoniomethyl-substituted ligand [7](3+), the trans/cis ratio is dependent on the ionic strength of the solution.

Synthesis and resolution of planar-chiral ruthenium-palladium complexes with ECE' pincer ligands.

Feel the pinch! Planar-chiral, cationic, ruthenium-palladium complexes based on eta(6),eta(1)-coordinated ECE' pincer ligands are synthesized as racemic mixtures by reacting ECE'-palladium complexes and [Ru(C(5)R(5))(MeCN)(3)](+) arenophiles (R=H or Me). Chiral resolution of the cationic complexes was achieved by using the chiral counterion [Delta-TRISPHAT](-), and solving the X-ray crystal structure of one diastereoisomer (shown here).

Probing the mer- to fac-isomerization of tris-cyclometallated homo- and heteroleptic (C,N)3 iridium(III) complexes.

We have developed techniques which allow for covalent tethering, via a "hetero" cyclometallating ligand, of heteroleptic tris-cyclometallated iridium(III) complexes to polymeric supports (for application in light-emitting diode technologies). This involved the selective synthesis and thorough characterization of heteroleptic [Ir(C,N) 2(C',N')] tris-cyclometallated iridium(III) complexes. Furthermore, the synthesis and characterization of heteroleptic [Ir(C,N) 2OR] complexes is presented.

Alpha-Tris(2,4-pentanedionato-kappa2O,O')chromium(III) at 290 and 110 K: a new delta phase at 110 K.

The crystal structure of the title compound, [Cr(C(5)H(7)O(2))(3)], has been determined at 290 and 110 K to provide information on thermal vibrations and disorder. The alpha polymorph at room temperature has been reported [Morosin (1965). Acta Cryst.

alpha-Tris(2,4-pentanedionato-kappa(2)O,O')cobalt(III) at 240, 210, 180, 150 and 110 K.

The crystal structure of the title compound, [Co(C(5)H(7)O(2))(3)], has been investigated by a multi-temperature measurement. In contrast to the isomorphous Al compound, the title compound exists in the studied temperature range as its monoclinic alpha polymorph (space group P2(1)/c) and does not undergo a phase transition. Rigid-body TLS analyses have been performed and the anisotropic thermal expansion tensor alpha(ij) has been determined.

alpha-Tris(2,4-pentanedionato-kappa(2)O,O')aluminum(III) at 240, 210, 180, 150 and 110 K: a new delta phase at 110 K.

The crystal structure of the title compound, [Al(C(5)H(7)O(2))(3)], has been investigated by a multi-temperature measurement to provide information on thermal vibrations and disorder in the structure. At 110 K, the structure of a new delta polymorph could be determined. A disorder-order phase transition takes place between 150 and 110 K and is klassengleich.