Schwingungsspektren und Normalkoordinatenanalyse von Dimethylzink, Dimethylzink‐d₆ und Diäthylzink

Abstract

Die IR‐ und Ramanspektren des flüssigen Diäthylzinks wurden Vermessen, empirisch zugeordnet und mit den mittels eines von Dimethylzink und Dimethylzink‐d6 übernommenen modifizierten Valenzkraftfeldes berechneten Schwingungsfrequenzen und ‐formen Verglichen.

Homogeneous Decomposition Mechanisms of Diethylzinc by Raman Spectroscopy and Quantum Chemical Calculations

“…Bond dissociation energies were calculated using Becke's three-parameter hybrid exchange functional combined with the Lee−Yang−Parr gradient-corrected correlation functional (B3LYP) and the 6-311G(d) basis set. This method and basis set specify the model chemistry used to calculate molecular optimized geometries, and atomic or molecular properties for the reaction species, i.e., Zn-containing molecules. − This model chemistry was also used to calculate the Raman active frequencies along with the symmetrical vibrational motions between zinc and carbon or zinc and hydrogen atoms in selected intermediate species. Calculated values of the rotational or vibrational frequencies allowed their partition functions to be evaluated to yield Gibbs energies of possible intermediates to judge which reactions are thermodynamically favored.…”

IR Spectra of n-Bu4M (M = Si, Ge, Sn, Pb), n-BuAuPPh3-d15, and “n-Bu” on a Gold Surface

“…As a first step in our investigation we decided to take a closer look at the IR spectra of alkyl groups attached to heavier metal atoms in general. Surprisingly little information on the assignment of IR spectra of this type of organometallics is available in the literature. − An example of a question that we are attempting to answer is whether the vibrations of the CH 2 group that is adjacent to the metal atom can be distinguished from those of more distant CH 2 groups, as has been claimed for alkylsilanes. , We chose n -butyl as a typical alkyl for which many gold surface IR spectra are now available and which is small enough for a detailed analysis. We prepared the organometallics 1 – 5 (Chart ) and (CH 3 CH 2 CH 2 13 CD 2 ) 4 Sn, [ 3­( 13 CD 2 ) ] (Chart ), measured their mid-IR spectra, used density functional theory (DFT) to help with band assignments in terms of group vibrations in the 1350–3500 cm –1 region that is most accessible in surface spectroscopy, and compared them with the polarization modulated IR reflection/absorption spectra (PM IRRAS) of butylated gold surfaces.…”

Towards degradable polyethylene: end-functionalised polyethylene (PE-X) and PE-I/LDPE blends from iron-catalysed chain growth of ZnEt2 with ethylene

“…The characteristic triplet for the ZnCH2 moiety is found at 0.30 ppm in the 1 H NMR and at 16.3 ppm in the 13 C NMR spectrum, as well as the in-plane rocking vibration at 628 cm -1 , typical for ZnCH2 units. 59 The high reactivity of the Zn-C bond can be exploited to prepare a range of end-functionalised PE-X compounds, as illustrated in Figure 2.…”

“…Polymer Chemistry 0.30 ppm in the 1 H NMR and at 16.3 ppm in the 13 C NMR spectrum, as well as the in-plane rocking vibration at 628 cm −1 , typical for ZnCH 2 units. 59 The high reactivity of the Zn-C bond can be exploited to prepare a range of end-functionalised PE-X compounds, as illustrated in Scheme 2 Hydrolysis of Zn(PE) 2 results in a distribution of linear alkanes. The Poisson distribution of the n-alkane oligomers allows quantitative 13 C NMR analysis to be used to estimate the mean chain length C n by comparing integrals for CH 3 with those for CH 2 signals (Table 1, last column).…”