Infrared Matrix Isolation and Density Functional Theory Study of Intermediates in the Reactions of OVCl₃ and CrCl₂O₂ with H₂O

Abstract

Initial and secondary intermediates in the reactions of OVCl3 and CrCl2O2 with H2O have been characterized by matrix isolation infrared spectroscopy and density functional calculations. Twin jet co-deposition of these reagents led to a series of infrared absorptions that are assigned to the 1:1 molecular complexes between these two species. Irradiation of these matrices with light of λ > 300 nm led to complete destruction of the bands of complexes, and the growth of a number of new bands. These are assigned to the Cl2V(O)OH and ClCr(O)2OH species, as well as to HCl arising from destruction of the complex. Identification of these species was supported by isotopic labeling (18O and 2H), as well as by B3LYP/6-311G+(d,2p) and B3LYP/LANL2DZ density functional calculations. Good agreement was observed between the experimental and computed frequencies. The overall yield of product was low for these system, and was probably a consequence of the low basicity of H2O.

Matrix isolation and theoretical investigation of the photochemical reaction of CrCl2O2 with benzenes substituted with electron withdrawing groups

“…In each case, the blanks were in good agreement with literature spectra [37][38][39][40][41], and with blanks run previously in this laboratory. Each blank experiment was then irradiated by the H 2 O/Pyrex-filtered output of a 200 W Hg arc lamp for 1.0 h and no changes were noted, other than in the Ar/ CrCl 2 O 2 blank, where the growth of very weak bands due to photochemical reaction with impurity H 2 O was seen [21]. Weak bands due to HCl impurity were noted in all of the experiments involving CrCl 2 O 2 .…”

“…Past studies in this laboratory have examined the matrixisolated products of the thermal and photochemical reactions of CrCl 2 O 2 , OVCl 3 , and OVF 3 with organic and inorganic substrates [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]. Specifically, two recent studies in this lab [33,34] examined the reactions of CrCl 2 O 2 with benzene and with methyl-substituted benzenes.…”

Matrix Isolation and Theoretical Study of the Photochemical Reaction of CrCl2O2 with Chloroethenes

“…6,7 This laboratory has studied the reaction of these transition-metal compounds and several related species with small organic and inorganic substrates containing a heteroatom. [8][9][10][11][12][13] These studies have permitted the identification of a sequence of intermediates in each system from which a reaction mechanism was (at least partially) deduced. Wistuba and Limberg have focused on the reaction of CrCl 2 O 2 with alkenes and alkynes 14,15 and have reported several novel intermediates.…”

Chemistry in low-temperature matrices

“…Here the products, formed in 100% yields, are Cl 2 V(O)OH and ClCr(O) 2 OH. 282 If VCl 4 is employed in place of OVCl 3 then it is clear that O-atom transfer cannot take place. With acetone VCl 4 forms a 1:1 complex; near UV irradiation, however, causes bands of this complex to grow.…”