The electronic properties of trigonal bipyramidal complexes of the copper(II) ion

Abstract

The e.s.r. and electronic spectra and magnetic moments of Cu(NH,),Ag(SCN), and [Cu(tren)NCS]SCN (tren = 2,2',2"-triaminotriethylamine) are reported and compared with the previously reported data for trigonal bipyramidal complexes of the copper(l1) ion. Theoretical expressions for the g-values for a copper(l1) ion in a trigonal bipyramidal configuration are derived and are shown to apply only to the Cu(NH,),Ag(SCN), complex. The energy levels 2€" and 2E' are shown to be separated by less than 2000 cm.-I and the magnetic moments of the trigonal bipyramidal complexes are in the range normally observed for copper(l1) complexes with a n orbitally non-degenerate ground state.

Co-ordination behaviour of a novel bisthiourea tripodal ligand: structural, spectroscopic and electrochemical properties of a series of transition metal complexes

“…This is the case for the essentially regular trigonal bipyramidal structure Cu(NH 3 ) 2 Ag(SCN) 3 which exhibits transitions at 12 800 and 14 500 cm −1 . 32 This is in good agreement with the continuous shape mapping calculations based on the solid state structure of 4 which indicate a slightly distorted trigonal bipyramid, albeit with some square planar character.…”

Tuning the magneto-structural properties of non-porous coordination polymers by HCl chemisorption

“…The isotropic spectra observed at room temperature fully agrees with an unresolved spectra arising from the distorted tetrahedral environment exhibited by the Cu site. However, at low temperatures, an inverse axial spectrum with g || < g  is found (with g || = 2.100 and g  = 2.255; g average = 2.20), indicating a dz 2 magnetic orbital, which is unusual for distorted tetrahedral environments but typical for penta-coordinated Cu(II) complexes with trigonal bipyramid geometries 38 . This might be due to the presence of a Cu-Cl···Cu interaction (Supplementary Fig.…”

Cyclic Amidines Complexes: Complexes of 5:6:11:12-Tetrahydro-2,8-dimethylphenhomazine with Copper(II), Nickel(II) and Zinc(H)

“…It is characteristically different from the spectra of planar copper(II) complexes of daco and dach 4 , which have only one broad band with maxima at about 20,000 cm -1 . The spectrum is also different from the spectra of trigonal bipyramidal complexes 15 but is found to be quite similar to the spectra of distorted six-coordinated complexes 16 -17 having chromophore CUN4O2. For copper(II) ion in tetragonally distorted octahedral environment three principal absorption bands are expected but only in few cases [18][19][20] been resolved either by Gaussian analysis or single crystal polarization studies, and are assigned to 2 Big -> 2 Aig, 2 Big -> 2 B2g and 2 Big^2Eg in order of increasing energy.…”