The monofunctionalized 1,4,7-triazacyclononane derivatives 1,4,7-triazacyclononane-N-acetate (L) and N-(2-hydroxybenzyl-1,4,7-triazacyclononane (HL) and their complexes with vanadium(IV)/(V). Localized and delocalized electronic structures in compounds containing the mixed valent [OV---O---VO] core |
| |
Authors: | Daniela Schulz Thomas Weyhermü ller Karl Wieghardt and Bernhard Nuber |
| |
Institution: | a Max-Planck-Institut für Strahlenchemie, Stifstrasse 34-36, D-45470, Mülheim an der Ruhr, Germany b Anorganisch-Chemisches Institut, Im Neuenheimer Feld 270, D-69120, Heidelberg, Germany |
| |
Abstract: | The synthesis of the tetradentate pendant arm macrocycles 1,4,7-triazacyclononane-N-acetate (L1) and N-(2-hydroxybenzyl)-1,4,7-triazacyclononane (HL2) and their coordination chemistry with vanadium(IV) and (V) are reported. The following mononuclear species have been prepared and characterized by UV-Vis, IR spectroscopy: L1VIVO(NCS)] (1), L1VO2]·H2O (2), L2VO(NCS)] (3), L2VO(NCS)]Cl (4), and L2VO2] (5). In addition, the dinuclear, mixed valent complexes L21V2O3]Br (6), L22V2O3](ClO4)·0.5acetone (7), and the homovalent complex L22V2O3](ClO4)2 (8) have been synthesized. Complexes 2, 3, 6 and 7 have been characterized by single crystal X-ray crystallography. Crystal data: 2, space group P21c,a=9.944(4),b=6.701(3),c=18.207(8)Å, β=102.88(3)°, V=1182.7 Å3, Z=4, Dcalc=1.51 g cm?3, R=0.049 based on 4760 reflections; 3, space group Pbca, A=11.003(6), b=14.295(7), C=20.21(1) Å, V=3178.8 Å3, Z=8, Dcalc=1,50 g cm?3, R=0.057 based on 1049 reflections; 6, space Pbcn, a=12.922(3), B=13.852(3), C=12.739(3) Å, V=2280.3 Å3, Z=4, Dcalc=1,75 g cm?3, R=0.047 based on 1172 reflections; 7, space group C2/c, A=23.553(9), B=13.497(5), C=20.951(8) Å, β=90.03(3)°, V=6660.2 Å3, Z=8, Dcalc=1.49 g cm?3, R=0.053 based on 3698 reflections. Complexes 6 and 7 are mixed valent V(IV)/(V) complexes containing the OV---O---VO]3+ core. In the solid state 6 belongs to class III (delocalized) and 7 to class I (localized) according to the Robin and Day classification of mixed valent compounds. A rationale for these differing electronic structures is given. |
| |
Keywords: | Crystal structures Electronic structures Vanadium complexes Azamacrocycle complexes |
本文献已被 ScienceDirect 等数据库收录! |
|