Absolute rate constants for the reactions of germylene and dimethylgermylene with dimethylgermane: the deactivating effect of methyl groups in heavy carbenes

Theoretical Study on the Reactivities of Stannylene and Plumbylene and the Origin of their Activation Barriers

“…Besides this, considering both the activation barrier and the reaction enthalpy obtained from the model calculations presented here, it is concluded that the greater the atomic number of the X center, the larger the activation energy, the less exothermic the insertion reaction, and therefore the more difficult is its insertion into the Ge À H bond of germane. These theoretical investigations are in agreement with some available experimental findings, especially for the germylene [20,22] and stannylene cases. [8] Methanol insertion reactions: The reaction of Me 2 X with ntype lone pair donors such as MeOH was also studied in this work.…”

Gas phase kinetic and theoretical studies of reactions of germylenes and dimethylstannylene

“…25 Besides, tetramethyldigermane, HMe 2 GeGeMe 2 H was also found to be a good precursor of GeMe 2 . 26 Silicon analogs of these compounds are known to be good photochemical sources of SiMe 2 in the gas phase. 10,25, 27 Moreover, GCP is known to produce GeMe 2 upon thermolysis, 28-30 a usually reliable indicator.…”

“…10 The room temperature rate constant for the interaction of GeH 2 with Me 2 GeH 2 was also measured for comparison (Table 1). 26 Both reac tions were supposed not to be pressure dependent by analogy with the SiH 2 + Me 2 SiH 2 reaction. 10 For the GeMe 2 + Me 2 GeH 2 reaction, the lack of a pressure de pendence was indicated by the fact that the total pressure varied (depending on the concentration of Me 2 GeH 2 ) during the experiments and no curvature in the second order plot (dependence of transient first order decay con stant, k obs , on the pressure of Me 2 GeH 2 ) was found.…”

“…Yet another operating factor is the weakening of the pre reaction complex. 26 Methyl groups are known to sta bilize SiMe 2 . It has a higher DSSE (128 kJ mol -1 ) than SiH 2 (94 kJ mol -1 ).…”

Time-resolved gas-phase kinetic study of the germylene addition reaction, GeH2 + C2D4, as a function of temperature and pressure: isotope effects and mechanistic complexities

“…4 We have recently begun a series of gas-phase studies of the kinetics of GeH 2 reactions by time-resolved means leading to the first directly measured rate constants for GeH 2 . [5][6][7][8][9][10][11][12][13][14] The group of King and Lawrance have also recently begun similar studies. [15][16][17] These investigations show that GeH 2 typically undergoes bond insertion reactions (into Ge-H, Si-H and O-H bonds), p-type addition reactions across C=C and C= =C bonds and reaction with lone pair donor molecules such as ethers.…”