Photochemistry of trans-diisothiocyanatobis(ethylenediamine)chromium(III). Nature and stereochemistry of the reaction

Crystal structure analyses of Rh2(bridge)4(BPh4)2.CH3CN and Rh2(TM4-bridge)4(PF6)2.2CH3CN. Further electronic spectral studies of binuclear rhodium(I) isocyanide complexes

“…No correlation effects have been accounted for. 6 M refers to atom related by x, '/ 2 -y, z. 0 The standard deviation given in parentheses following an average bond distance or angle, x, is defined as = [ ,•( ,• -x)2/(N -1)] U2, where N is the number of observations, x,•.…”

“…Again, scattering factors for Rh were from Cromer and Waber,12 those for C, N, P, and F from ref 13, and those for hydrogen from 0 Band positions in nm; e X 10'3 values in parentheses. 6 Measured in aqueous solution at 25 °C; all other spectra were recorded in CH3CN solution at 25 Stewart et al 14 The quantity minimized in the least-squares calculations was £w[F02 -(1 /s2)(Fc2)]2, where w = l/o2(F02) and sscale factor. Anisotropic refinement of all nonhydrogen atoms converged at an R index of 0.15.…”

Competing Thermal and Photochemical Ligand Substitution Reactions of the Dimetallacycle (CO)4Mo(μ-PMD)2Mo(CO)4 (PMD = Pentamethylenediazirine). Mechanistic Information from Entering Nucleophile and Pressure Dependences

“…It is well-known that the photochemical reaction path can differ distinctly from that for the thermal reaction, particularly where the products are also different for such reactions. , Kinetic investigations on photochemical and thermal ligand substitution reactions of complexes such as M(CO) 4 (diimine), − (CO) 4 M(μ-PMD) 2 M(CO) 4 , , and M(CO) 5 L − (M = Cr, Mo, W; L is a derivative of pyridine; μ-PMD = 3,3-pentamethylenediazirine), which all possess the characteristics of a higher energy ligand field (LF) excited state and a lower lying metal to ligand charge to transfer (MLCT) state, have been the subject of numerous studies in organometallic chemistry. The results of these studies have shown that LF excitation results primarily in breakage of the M−CO bond in M(CO) 4 (diimine) complexes.…”

Photochemistry of trans-[Cr(en)2Br2]+ and trans-[Cr(en)2Cl2]+

“…Models based upon properties of quartet (and doublet) states have been proposed (5)(6)(7)(8), tested (6,(9)(10)(11)(12)(13), and extended (1 1, 14, 15). Consequently, some degree of unanimity exists regarding the principles enabling qualitative prediction of reaction modes and approximate relative quantum yields in aqueous solutions.…”