Solvation of dichlorocarbene: complexation with aryl ethers.
Dichlorocarbene (CCl(2)), generated by laser flash photolysis of dichlorodiazirine, formed pi- and O-ylidic complexes with aromatic ethers such as anisole, 1,3-dimethoxybenzene, 1,3,5-trimethoxybenzene, dibenzofuran, and dibenzo-18-crown-6 and with the aromatic ester phenyl acetate. These complexes were visualized by UV-vis spectroscopy, and they retarded the addition of CCl(2) to tetramethylethylene by factors of 18-152. Computational studies based on density functional theory provided structures and energetics for the transient species and rationalized their absorption spectra. Complexes were not observed between CCl(2) and simple, nonaromatic ethers such as THF, dioxane, or 18-crown-6, nor did these ethers much affect the addition rate of CCl(2) to tetramethylethylene. Computations also suggested that pi-complexes of CCl(2) and, e.g., mesitylene and durene, were energetically reasonable transients. Although these species were not detected spectroscopically, the aromatic compounds did slow the addition of CCl(2) to tetramethylethylene by factors of 15 and 31, respectively.
Moss
Robert A
RA
Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, New Brunswick, New Jersey 08903, USA. moss@rutchem.rutgers.edu
Wang
Lei
L
Odorisio
Christina M
CM
Zhang
Min
M
Krogh-Jespersen
Karsten
K
D000840:Anisoles / Q000737:chemistry; D001572:Benzofurans / Q000737:chemistry; D003198:Computer Simulation; D043844:Crown Ethers / Q000737:chemistry; D004987:Ethers / Q000737:chemistry*; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry*; D008956:Models, Chemical; D010696:Phloroglucinol / Q000031:analogs & derivatives / Q000737:chemistry; D010782:Photolysis; D012996:Solutions
D000840:Anisoles; D001572:Benzofurans; D043844:Crown Ethers; D004987:Ethers; D006843:Hydrocarbons, Chlorinated; D012996:Solutions; C015560:1,3,5-trimethoxybenzene; C002564:dibenzo-18-crown-6; C031201:1,3-dimethoxybenzene; C023614:dibenzofuran; C060998:anisole; D010696:Phloroglucinol; C004260:dichlorocarbene