Synthesis, spectroscopic characterisation and X-ray crystal structures of acetato(di-2-pyridylamine)nitritocopper(II) monohydrate and (di-2-pyridylamine) dinitritocopper(II)

The crystal and molecular structures of the complexes [Cu(dpyam) (O2CCH3)(N O2)]. H2O (I) and [Cu(dpyam)(NO2)(2)] (II), dpyam = di-2-pyridylamine, have been determined. Both complexes consist of neutral mononuclear units, the copper(II) environments in (I) and (II) are best described as tetrahedral-d istorted octahedral with elongated axial positions (4 + 2). The equatorial plane in (I) comprises the two dpyam nitrogen atoms at 1.997(2) and 1.963(2 ) Angstrom, and two oxygen atoms of two oxyanions (acetate and nitrite anio ns) at 2.039(2) and 1.967(2) Angstrom, with the axial positions occupied by another two oxygen atoms of the acetate and nitrite anions at the longer C u-O distances of 2.484(2) and 2.436(2) Angstrom. The equatorial plane in (I I) is composed of the two dpyam nitrogen atoms at 1.986(1) and 1.966(1) A, and two oxygen atoms of each acetate group at 2.017(1) and 2.003(1) Angstro m, with the apical positions filled by the second oxygen atoms of each nitr ite group at the longer Cu-O distances of 2.469(2) and 2.431(2) Angstrom. ( C) 1999 Elsevier Science Ltd. All rights reserved.