Ab initio theoretical study on geometries, chemical bonding, and infrared and electronic spectra of the M2O72- (M = chromium, molybdenum, tungsten) anions

cis-Aquabis(2,2′-bipyridine-N,N′)[dichromato(2–)-O1]nickel(II)

“…The two tetahedral CrO 4 groups share one O atom (O4) thus forming a dichromate anion in an almost eclipsed conformation. The CrÐOÐCr bridging angle is 129.2 (2) , a value which is in the range of previously reported dichromatecontaining compounds (Mestres et al, 1993;Martõ Ân-Zarza et al, 1995). The bridging CrÐO bonds are 1.744 (3) and 1.812 (3) A Ê for Cr1ÐO4 and Cr2ÐO4, respectively.…”

Surface-Enhanced Raman Spectroscopy (SERS) and Molecular Modeling of the Chromate Interaction with 4-(2-Mercaptoethyl)Pyridinium

“…The 3-21G* basis set has been shown to yield reasonably good geometrical results for these and other Cr(VI) species. 20,23,24 Figure 2 shows the structure of chromate as calculated using the B3LYP/3-21G* model. Bond angles and bond lengths are summarized in Table S-1, Supporting Information.…”

Syntheses, crystal structures and magnetic properties of one-, two- and three-dimensional 2,2′-bipyrimidine-containing copper(II) complexes

“…The Cr(1)᎐O(7)᎐Cr(2) bridging angle is 125.1(1)Њ, a value which is in the range of previously reported dichromate-containing compounds. 15, 16 The bridging Cr᎐O bonds are 1.759(2) and 1.803(2) Å for Cr(1)᎐O(7) and Cr(2)᎐O(7), respectively. They are longer than the terminal Cr᎐O ones, where the maximum and minimum bond lengths are 1.675(2) [Cr(1)᎐O( 6)] and 1.596(2) Å [Cr(1)᎐O( 5 The metal-metal separation across bridging bipym in 1 is 5.646(1) Å, to be compared with 5.597(3) Å in compound 4.…”