Girolamo LaMonica

UNIQUE FORMATION OF A CRYSTAL PHASE CONTAINING CYCLIC OLIGOMERS AND HELICAL POLYMERS OF THE SAME MONOMERIC FRAGMENT

The yellow, microcrystalline compound [Cu(pymo)] (Hpymo=2-hydroxypyrimidine) has been characterized with the newly emerging technique of ab initio X-ray powder diffraction. A unique and unprecedented crystal phase containing cyclic oligomers and infinite helical polymers (see picture) of the same monomeric fragment is selectively formed upon reaction of [Cu(CH3 CN)4 ][BF4 ] and Hpymo with NEt3 .

Alkyne oligomerization catalyzed by molybdenum(0) complexes

Abstract Three new molybdenum(0) complexes, [Mo(CO)3(Hpz)3] (1), [Mo(CO)2(Hpz)2(DMAD)2] (2), (DMAD=dimethyl acetylenedicarboxylate) and [Mo(CO)3(1-Me-imidazole)3] (3) were synthesized and characterized. Their activity and selectivity in alkyne cyclotrimerization and co-trimerization reactions was investigated. The molecular structures of 1 and 2 have been determined by unconventional powder and standard single-crystal diffraction methods, respectively. 1 consists of a pseudo-octahedral complex of C3 symmetry, with the ligands in fac disposition; complex 2, of idealized C2 symmetry, is obtained by substitution of one CO and one pyrazole in 1 by two DMAD ligands, and shows the rare trans configuration of π-bound acetylenic moieties.

Thermally robust metal coordination polymers: The cobalt, nickel, and zinc pyrimidin-2-olate derivatives

A number of coordination polymers of the pymo ligand (Hpymo = 2-hydroxypyrimidine) have been prepared and fully characterized by chemical, spectroscopic, and thermal analyses. Their complete crystal structures have been solved ab initio from laboratory X-ray powder diffraction data and ultimately refined by the Rietveld method. The M(pymo)2 species (M = Co, Ni, Zn) consist of structurally related threedimensional frameworks of very high thermal stability (decomposing under N2 only at T . 550 °C), with the metal atoms, linked by μ2-η-η (N;N9) (Co, Zn) or μ2-η-η (N,O;N9)

Oligomerization and polymerization of alkynes catalyzed by rhodium(I) pyrazolate complexes

Three new Rh(I) derivatives containing the dcmpz ligand (Hdcmpz: 3,5-dicarbomethoxypyrazole) have been prepared and employed as catalysts or catalyst precursors in the cyclotrimerization of terminal and internal alkynes and in the polymerization of ethyne to polyacetylene.

Pyrazolato Metal Complexes: Synthesis, Characterization and X-ray Crystal Structures of Polynuclear Organometallic Re–Mn Derivatives

By reacting [Re(CO)3(Hpz)2(pz)] (Hpz = pyrazole) with characterized in the solid state by single crystal X-ray diffraction analysis and were showed to contain Re···Mn [Mn(CO)5Br] in toluene in the presence of Et3N, the dinuclear complex [(CO)3Re(pz)3Mn(CO)3](Et3NH) (1) was interactions linked by and tris-μ2-pyrazolato bridges. In 5, a short [2.397(4) A] tris(μ2-oxo)bridged MnIV–MnIV contact is obtained. The reaction of 1 with molecular oxygen affords