SYNTHESIS AND CHARACTERIZATION OF COPPER(I) DERIVATIVES WITH NITROGEN-DONOR LIGANDS .2. DIHYDRIDOBIS(1H-PYRAZOL-1-YL)BORATE AND TETRAKIS(1H-PYRAZOL-1-YL)BORATE - THE X-RAY CRYSTAL-STRUCTURE OF [PZ(2)B-(MU-PZ)(2)-CU(PPH(3))(2)]

Bis(triarylphosphine)copper(I) derivatives with the anionic tetrakis(1H-pyrazol-1-yl)borato (pzTp) or dihydridobis(1H-pyrazol-1-yl)borato (Bp) have been prepared from (Ar3P)(2)CuNO3 and KpzTp or KBp, and characterized through IR and H-1, C-13 and P-31 NMR. The complexes contain tetrahedral Cu-I and a bidentate ligand. The pzTp ones are fluxional in solution with all pyrazolyl groups equivalent down to similar to -60 degrees C. The X-ray crystal structure of (Ph(3)P)(2)CupzTp has been resolved. The Cu-I atom has distorted tetrahedral cordination and shows Cu-N distances of 2.087(3), 2.051(3) Angstrom and Cu-P distances of 2.273(1), 2.359(1) Angstrom; the N-Cu-N and P-Cu-P angles are 92.6(1)degrees and 119.82(4)degrees, respectively, whereas the N-Cu-P angles range from 99.21(9) to 119.76(9)degrees. The six-membered B(NN)(2)Cu ring adopts the boat form.