No abstract

Two 1,5-diaza-3,7-diphosphacyclooctane (P 2 N 2 ) ligands with alkyl-substituted phosphines have been synthesized via a versatile method that allows for improved control of the phosphine substituent. The methyl-and benzylsubstituted phosphine P 2 N 2 ligands (P Me 2 N Ph 2 and P Bn 2 N Ph 2 ) were synthesized and characterized by 31 P{ 1 H} NMR, 1 H NMR, and elemental analysis, and their corresponding [Ni(P R 2 N Ph 2 ) 2 ](BF 4 ) 2 complexes were synthesized and characterized by 31 P{ 1 H} NMR, 1 H NMR, and electrochemistry. The structure of the complex [Ni(P Me 2 N Ph 2 ) 2 ](CF 3 SO 3 ) 2 was characterized by X-ray crystallography.

A series of four new bis-P 2 N 2 (P 2 N 2 = 1,5-diaza-3,7-diphosphacyclooctane) Pd(II) complexes were synthesized and characterized by spectroscopy, electrochemistry, and X-ray crystallography. The compounds crystallize in square planar or tetrahedrally distorted geometries and exhibit a single quasireversible 2e − Pd(II/0) redox couple in voltammetric studies.[Pd(P Ph 2 N Bn 2 ) 2 ] 2+ and [Pd(P Me 2 N Ph 2 ) 2 ] 2+ were tested for electrochemical CO 2 reduction in the presence of excess protons and found to preferentially produce H 2 .

A new hexagonal bipyramidal Ni8 cluster is reported and its magnetic behaviour is analyzed. The molecular structure consists of a hexagonal wheel capped by two additional apical Ni(2+) ions. This structure supports ferromagnetic superexchange interactions between adjacent Ni(2+) ions in the wheel and an antiferromagnetic superexchange interaction between the wheel and apical Ni(2+) ions.