Crystal and molecular structure of bis[(+)-N,.alpha.-dimethylphenethylammonium] tetrachlorocuprate(II). Relation between the electronic spectrum and the distortion of the tetrachlorocuprate chromophore from tetrahedral symmetry

Crystal Structure of Bis(3-Diethylamino-5-phenyl-1,2,4-dithiazolium) Hexachlorodicuprate, (dpd)2Cu2Cl6, at 120 K.

“…Using the expression v (max) = 144.59 -9784 cm-1 [5] the difference between the absorption maximum of the ligand field spectrum at the two temperatures : This difference can explain the change of the colour of the compound (brown -yellow). Our re sults thus confirm that the thermochromism in this kind of coordination compounds can be attributed to the changes in the coordination geometry of the metal ion.…”

Features of Structure, Geometrical, and Spectral Characteristics of the (HL)2[CuX4] and (HL)2[Cu2X6] (X = Cl, Br) Complexes

“…Two types of coordination exists: the "common" one with ionic radii of about 0.5 Ǻ and semi-coordinated where the bond lengths are 0.3 -1.0 Ǻ longer (Hathaway, 1982). The shape of coordination polyhedra changes from square planar (Harlow et al, 1975) to distorted tetrahedral (Diaz et al, 1999). The degree of distortion of CuX 4 2-coordination polyhedra is determined by the mean value of the flattering or trans-angle  (Fig.1).…”

“…Сu 2 X 6 2-structures One of the common types of planar anionic halocuprates(II) is a pseudo-planar dibridged structure (Harlow et al, 1975). Each of Cu(II) atom forms a primary planar square configuration.…”

Structural, spectroscopic, and electron paramagnetic resonance studies on two solid phases of bis-dipropylammonium tetrachlorocuprate(II) (DPACC)

“…Such an empirical relation has subsequently been used in several different contexts (7,20,31). With several new C U C~~~-structures now available, we wish to extend this analysis to include a great deal more data, and make available a convenient reference for other workers as to the probable geometry of the anion in systems containing CUCI,~-.…”

“…This transition has also been observed by Tomovic et al (6). There has also been continued interest in correlating the d-d transition energies of tetrahedrally coordinated Cu(I1) ions with varying degrees of tetragonal distortion (7,8). The purpose of this paper is to report the crystal structures and spectroscopic properties of two solid phases of bisdipropylammonium tetrachlorocuprate(II) (DPACC) (the a phase existing between the transition temperature at 330 K and the melting point at 353 K, the P phase existing below 330 K), and to correlate the maximum d-d transition energy of the room Can.…”