Syntheses, characterization, and crystal structures of two trans six-coordinate germianium(IV) complexes of H2tmtaa (5,14-dihydro-6,8,15,17-tetramethyidibenzo[b,i][1,4,8,11]-tetraazacyclotetradecine)

The reaction of Ge(trntaa)Cl-2, [5,14-dihydro-6,8,15,17-tetramethyldibenzo[b,i][ 1,4,8,11 ]tetrazacyclotetradecine (H(2)tmtaa)] and sodium cyanate or sodium acetate under mild conditions results in mononuclear six-coordinate trntaa Ge(IV) complexes, Ge(trntaa)X, [X - NCO (I); X = OCOCH3, (2)]. containing Ge-N or Ge-O bonds, respectively. Pie complexes, (1) and (2), have been characterized by IR spectra, UV spectra, mass spectra, NMR spectra, and elemental analyses, as well as DSC measurements. X-ray crystal structures of (1) and (2) reveal that the tmtaa ligand of the complexes retains the characteristic saddle-shaped configuration of H(2)tmtaa and the complexes have adopted six-coordinate geometries in which two substituents are in trans positions.