202208-99-9Relevant articles and documents
Homo- and cross-[2+2]-cycloaddition of 1,1-diphenylsilene and 1,1-diphenylgermene. Absolute rate constants for dimerization and the molecular structures and photochemistry of the resulting 1,3-dimetallacyclobutanes
Toltl, Nicholas P.,Stradiotto, Mark,Morkin, Tracy L.,Leigh, William J.
, p. 5643 - 5652 (1999)
Absolute rate constants for the head-to-tail [2+2]-dimerization of 1,1-diphenylsilene and 1,1-diphenylgermene have been determined in hexane and isooctane solution at 23 °C by laser flash photolysis, using the corresponding 1,1-diphenylmetallacyclobutanes
Arrhenius parameters for the head-to-tail dimerizations of 1,1-diphenylsilene and 1,1-diphenylgermene in solution
Morkin, Tracy L.,Leigh, William J.
, p. 4537 - 4541 (2001)
Arrhenius parameters for the head-to-tail dimerization of 1,1-diphenylsilene and 1,1-diphenylgermene have been determined in hexane solution by nanosecond laser flash photolysis. Both compounds exhibit near-zero activation barriers over the range 0-60°C a
Competing germene and germylene extrusion from photolysis of 1,1-diarylgermacyclobutanes. Substituent effects on germene reactivity
Leigh, William J.,Potter, Gregory D.,Huck, Lawrence A.,Bhattacharya, Adroha
, p. 5948 - 5959 (2009/04/13)
Direct irradiation of 1,1-diphenyl-, 1,1-bis[4-(trifluoromethyl)phenyl]-, and 1,1-bis[3,5-bis(trifluoromethyl)phenyl]germacyclobutanes (2, 4, and 5, respectively) in methanolic C6D12 solution affords products consistent with the competing formation of the corresponding 1,1-diarylgermenes and diarylgermylenes, along with ethylene and cyclopropane. The relative yields of the two Ge-containing primary products (germene:germylene) vary with the extent of CF3 substitution on the aryl rings, decreasing in the order 2 > 4 > 5. As was reported previously for 2, laser flash photolysis of 4 and 5 in hexane, acetonitrile, or tetrahydrofuran solution allows the detection of the corresponding transient 1,1 -diarylgermenes (6 and 7, respectively), which have been identified on the basis of their UV/vis spectra (λmax ～325 nm) and quenching studies with MeOH, tert-butyl alcohol (t-BuOH), acetic acid (AcOH), n-butylamine (M-BuNH2), and acetone. In carefully dried hexane solution, weak transient absorptions assignable to the corresponding germylenes and their respective (digermene) dimers are also observed; in the case of 5, these assignments have been confirmed by the results of steady-state and laser photolysis experiments with 1,1-bis[3,5-bis(trifluoromethyl)phenyl]-2,3- dimethyl-1-germacyclopent-3-ene (14c), which affords the germylene exclusively, in substantially higher quantum yield. The reactivities of the germenes toward each of the various substrates studied vary modestly with aryl substituent, increasing in the order acetone 2 a much more dominant role in the reactions of the Ge=C bond with nucleophilic reagents than is the case with the homologous silene derivatives, whose reaction kinetics are controlled primarily by substrate nucleophilicity.
Bis-, tris- and tetrakis(lithiomethyl)germanes: New building blocks for organogermanium compounds
Strohmann, Carsten,Wack, Eric
, p. 1570 - 1578 (2007/10/03)
Bis(lithiomethyl)germanes, R2Ge(CH2Li)2, tris(lithiomethyl)germanes, RGe(CH2Li)3, and tetrakis(lithiomethyl)germane, Ge(CH2Li)4, were prepared by the reductive C-S bond cleavage with lithium naphthalenide (LiC 10H8) or lithium p,p′-di-tert-butylbiphenylide (LiDBB) and characterized by trapping with Bu3SnCl. The bis(lithiomethyl)germanes were used for the synthesis of 1,1-dimethyl-3,3- diphenyl-1-germa-3-silacyclobutane, 1,1 -diethyl-3,3-diphenyl-1-germa-3- silacyclobutane, 1,1,3,3-tetraphenyl-1-germa-3-silacyclobutane and 1,1,3,3-tetraphenyl-1,3-digermacyclobutane. The single-crystal X-ray diffraction studies of methyltris(phenylthiomethyl)germane and tetrakis(phenylthiomethyl) germane, starting materials for the corresponding poly(lithiomethyl)germanes, indicate tetrahedrally arranged substituents at the germanium atoms.
Direct detection of i,i-diphenylgermene in solution and absolute rate constants for germene trapping reactions
Toltl, Nicholas P.,Leigh, William J.
, p. 1172 - 1178 (2007/10/03)
Direct irradiation of 1,1-diphenylgermetane in hexane solution affords 1,1,3,3-tetraphenyl-1,3 digermetane in high chemical yield. Photolysis in the presence of aliphatic alcohols leads instead to the formation of the corresponding alkoxymethyldiphenylgermane. These results are consistent with the formation of 1.1-diphenylgermene as a primary photochemical product from photolysis of the germetane. Nanosecond laser flash photolysis of the compound in hexane, acetonitrile, or tetrahydrofuran gives rise to the formation of a transient, assignable to the germene on the basis of its second order decay kinetics, UV spectrum (λ(max) = 325 nm), and the fact that it is quenched by addition of alcohols and acetic acid. Absolute rate constants for reaction of 1.1 diphenylgermene with methanol, ethanol, 2-propanol, tert-butyl alcohol, acetic acid, the O-deuterated isotopomers, and acetone were determined in the three solvents, using the germetane as the O-deuterated isotopomers, and acetone were determined in the three solvents, using the germetane as the precursor. The kinetics and mechanisms of these germene trapping reactions are discussed and compared to those of silenes.
