Several alkynyl(tricarbonyl)diaminerhenium complexes were prepared from corresponding halo complexes and silver acetylides. With the diamine N,N′-dimethylpiperazine the compounds were found to be sufficiently stable to allow synthetic transformations on the acetylide ligand as well as purification by chromatography and subsequent substitution of the diamine ligand by stronger ligands such as phenanthrolines or isocyanides.Complexes of the type Re(alkynyl)(CO)3(diamine) have been prepared. With N,N′-dimethylpiperazine as the diamine the compounds are sufficiently stable to allow chemical modifications of the acetylide ligand and subsequent substitution of the diamine by stronger ligands.

Several platinum(II) isocyanide complexes of the type PtI2(CNC6H2-2,6-R2-4-CC-(C6H2-3,5-R′2-4-(R or S)-OCHMeCn−1(H2(n−1)CH3))2 have been prepared and their mesomorphic properties have been investigated. The complexes with R=Me, R′=H, and n=4–7 exhibit a broader N* phase than the corresponding complexes with R=R′=H, indicating that the methyl substituents on the phenylisocyanide group improve the liquid crystal properties by creating a smooth transition between the bulky PtI2 center and the more slender organic units. The complexes with R=Me and R′=Me exhibit a SmA phase. The presence of methyl groups in the R′-positions in addition to the methyl groups in the R-positions increases the melting point, but does not significantly change the clearing temperature. For the complexes with R=Me and R′=H the temperature-dependent pitches of the N* phase range from 350 to 400 nm.Several platinum(II) isocyanide complexes of the type PtI2(CNC6H2-2,6-R2-4-CC-(C6H2-3,5-R′2-4-(R or S)-OCHMeCn−1(H2(n−1)CH3))2 have been prepared. The influence of methyl substituents in the positions R and R′ on the mesomorphic properties has been evaluated.

cis-Diisocyanide metal complexes of the types cis-W(CNR)2(CO)4, cis-ReCl(CNR)2(CO)3, and Fe(η5-C5H5)Cl(CNR)2 and fac-triisocyanide metal complexes of the types fac-W(CNR)3(CO)3 and [Fe(η5-C5H5)(CNR)3]Cl have been prepared. The isocyanides are of the type 4-CNC6H2-3,5-i-Pr2-f, whereby the functionalities f are capable of forming strong coordinative bonds to transition metals (f=CCH, CC-4-C5H4N, or CC-4,4′-biphenyl-C6H2-3,5-i-Pr2-4-NC) or capable of being interconnected with each other by covalent bond formation (f=Br, I, CCSiMe3, CCH). The molecular structures of cis-W(4-CN-3,5-i-Pr2-C6H2CC-4-C5H4N)2(CO)4, cis-ReCl(4-CN-3,5-i-Pr2-C6H2CCH)2(CO)3, and Fe(η5-C5H5)Cl(4-CN-3,5-i-Pr2-C6H2CC-4-C5H4N)2 have been determined by X-ray crystallography.