994-79-6Relevant academic research and scientific papers
Closed-shell ion pairs: Cation and aggregate dynamics of tetraalkylammonium salts in a ion-pairing solvent
Mo, Huaping,Wang, Anping,Wilkinson, Patricia Stone,Pochapsky, Thomas C.
, p. 11666 - 11673 (1997)
Tetrabutylammonium ion (1) forms tight ion pairs with small anions (Cl-, BH4-) in GDCl3 solution. These ion pairs aggregate as a response to increasing solution concentration with little temperature dependence. Maximum aggregate size is approximately four ion pairs, as measured by comparing self-diffusion coefficients of the aggregates with that of an internal nonaggregating standard of the same shape and nominal size, tetrabutylsilane (2). The magnitudes of steady state interionic 1H{1H} NOEs observed between 1 and the BH4- anion in CDCl3 as a function of temperature in solutions of fixed concentration are well fit to the standard theoretical expression by assuming a single aggregate size that is independent of temperature. A simplified model-free analysis was applied to steady state 15N{1H} NOE and 15N T1 measured at several magnetic field strengths, using 15N-labeled 1 to obtain estimates for reorientational correlation times for the ion aggregates. A similar analysis of 13C{1H} NOE and 13C T1 gives local effective correlation times for C-H bond vectors of the 1-CH2 carbon of 1 and order parameters relating the local motion to overall cation motion. Comparison of these correlation times with those obtained from analysis of 29Si{1H} NOE, 13C{1H} NOE, and 13C T1 for silane 2 provides an estimate of aggregate size which is independent of that obtained by diffusion, with good agreement between the different approaches.
IR Spectra of n-Bu4M (M = Si, Ge, Sn, Pb), n-BuAuPPh3-d15, and "n-Bu" on a Gold Surface
Kaleta, Ji?í,Bednárová, Lucie,?í?ková, Martina,Wen, Jin,Kaletová, Eva,Michl, Josef
, p. 4619 - 4625 (2017/07/11)
Observed and DFT-calculated IR spectra of n-Bu4M (M = Si, Ge, Sn, Pb), (CH3CH2CH213CD2)4Sn, and n-BuAuPPh3-d15 are reported and assigned. The asymmetric CH stretching vibration of the CH2 group adjacent to the metal atom appears as a distinct shoulder at ~2934 cm-1, whereas for other CH2 groups it is located at ~2922 cm-1. The characteristic peak at ~2899 cm-1 is attributed to an overtone of a symmetric CH2 bend at ~1445 cm-1. In n-BuAuPPh3-d15, the CH stretching vibrations of the butyl group are shifted to lower frequencies by ~10 cm-1, and two possible rationalizations are offered.
Pentacoordinate silicon compounds. Reactions of silatranes with nucleophiles
Cerveau, G.,Chuit, C.,Corriu, R. J. P.,Nayyar, N. K.,Reye, C.
, p. 159 - 168 (2007/10/02)
The reactions of hydro, organyl and halosilatranes with nucleophiles have been studied.Substitution involving cleavage of equatorial Si-O bonds is always observed.Silitranes exhibit reactivity quite different from that of analogous trialkoxysilanes or anionic pentacoordinate silicon compounds.
