Syntheses, Crystal Structures And Properties Of Metal Complexes Of 4-benzyl-3,5-dimethylpyrazolate

Metal pyrazolate complexes have received much attention as a result of their rich structural chemistry, their application in advanced material and catalysis. These metal pyrazolates were mostly prepared through protonolysis, metathesis, oxidation-reduction, and CS2 elimination. In this thesis, three metal 4-benzyl-3,5-dimethylpyrazolate (bdmpz) complexes, three metal complexes of 4-benzyl-3,5-dimethylpyrazole (bdmpzH) and one hexanuclear complex [Ag(bzdmpymt)]6 (bzdmpymtH =5-benzyl-4,6-dimethylpyrimidine-2-thione) were isolated and structurally characterized. The main findings in this thesis are described as follows. 1 Complex Co(bdmpzdtc)3·H2O (1·H2O) (bdmpzdtc=4-benzyl-3,5-dimethyl- pyrazole-1-dithiocar-boxylate) was prepared in an almost quantitative yield from the reaction of CoCl2·6H2O with three equiv. of Kbdmpzdtc at ambient temperature. However, analogous reactions of Kbdmpzdtc with NiCl2·6H2O or ZnCl2 gave rise to [Ni(bdmpzdtc)(bdmpz)]2 (2) and [Zn4(μ-bdmpz)6(μ-OH)2]2·DMF·H2O (3·DMF·H2O), respectively. 1–3 were characterized by IR, EA, and their crystal structures were determined by X-ray diffraction. For 1, the central Co atom is coordinated by three bdmpzdtc ligands through N and S atoms, forming and octahedral coordination geometry. For 2, two Ni atoms are held together by one pair bdmpz- anions, and one pair of bdmpzdtc- anions, forming a dimeric structure. For 3, four [Zn2(μ-bdmpz)(μ-OH)] fragment are linked by four pairs ofμ-bdmpz ligands, thereby forming a centro-symmtrical metallomacrocyclic crown structure.2 The reactions of ZnCl2, CuCl2·2H2O and CdCl2·2.5H2O with bdmpzH, produced another three complexes ZnCl2(bdmpzH)2 (4), Cu4Cl6O(bdmpzH)4 (5) and [Cd4Cl8(bdmpzH)8]n (6). 4-6 were characterized by IR, EA, and their crystal structures were determined by X-ray diffraction. For 4, the central Zn is coordinated by two N atoms of two bdmpzH ligands and two chlorides, forming a tetrahedral coordination geometry. For 5, four Cu atoms are linked together byμ4-O atom and four chlorides to form a [Cu4O] adamantine type structure. Complex 6 has a 1D chain structure in which each [Cd4(μ-Cl)8(bdmpzH)8] unit is interconnected by pairs ofμ-Cl bridges.3 The reaction of AgAc with bzdmpymtH in MeOH resulted in the formation of compound [Ag6(bzdmpymt)]6·2MeOH (7·2MeOH), which was structurally characterized by EA, IR, and and its crystal structure was determined by single-crystal X-ray diffraction. An X-ray analysis revealed that six Ag atoms are held together by six bzdmpymt ligands through six pairs of S and N atoms, thereby forming a water-wheel-shaped structure.