Debye temperature and melting point of II‐VI and III‐V semiconductors

In this paper, simple relations are proposed for the calculation of Debye temperature θ_D and melting point T_mof II‐VI and III‐V zincblende semiconductors. Six relations are proposed to calculate the value of θ_D. Out of these six relations, two are based on plasmon energy data and the others on molecular weight, melting point, ionicity and energy gap. Three simple relations are proposed to calculate the value of T_m. They are based on plasmon energy, molecular weight and ionicity of the semiconductors. The average percentage deviation of all nine equations was calculated. In all cases, except one, it was estimated between 3.34 to 17.42 % for θ_D and between 2.37 to 10.45 % for T_m. However, in earlier correlations, it was reported between 10.59 to 33.38% for θ_D and 6.96 to 14.95% for T_m. The lower percentage deviation shows a significant improvement over the empirical relations proposed by earlier workers. The calculated values of θ_D and T_m from all equations are in good agreement with the available experimental values and the values reported by different workers. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Still Elusive – Pd(II)-Mediated Base Pairing by an Acetophenone Oxime Palladacycle within 15N-Labelled Double-Helical Oligonucleotides

Both α and β anomers of an acetophenone C-nucleoside were synthesized and incorporated in the middle of short oligodeoxynucleotides. The ketone oligonucleotides were converted to ¹⁵N-labelled oxime oligonucleotides by treatment with ¹⁵N-hydroxylamine and, finally, cyclopalladated by treatment with lithium tetrachloropalladate. Comparison of the UV melting profiles of duplexes bearing the β anomer of either the palladacyclic or the metal-free oxime C-nucleoside suggested formation of a stable Pd(II)-mediated base pair, especially with adenine or thymine as the base pairing partner. Melting profiles of the corresponding duplexes bearing the α anomer were much more convoluted, precluding meaningful comparison. ¹⁵N NMR spectra were obtained for the β anomeric oxime oligonucleotide as well as its palladacyclic derivative but the signals unfortunately diminished below detection limit when the latter was hybridized with a complementary strand placing a ¹⁵N3-labelled thymine opposite to the palladacyclic residue.