Niobium and vanadium iminophosphinimide complexes

The iminophosphinimide complexes [Ar(R)N]3M(NPNBut) (M = V, Nb) were prepared from the corresponding anionic nitride species ([Ar(R)N]3M identical to NNa)2 by way of a four-step synthetic strategy.     

Raman spectrum and structure of solid P2Cl4

The Raman spectrum of liquid and solid polycrystalline P₂Cl₄ has been recorded from 30 to 700 cm^–1. The far infrared spectrum of the solid has also been reinvestigated. From these data, it is necessary to reassign the P-P stretch (a _g), the PC1₂ rock (a _u) and the PCl wag (b _u). Three lattice modes were observed in the Raman spectrum whereas none was found in the infrared spectrum. No correlation field splitting was observed for any of the intramolecular fundamentals. Although the vibrational data for the crystalline state is best interpreted in terms of atrans (C _2h, 2/_m) conformation, there is some evidence that another form may be present, in small amounts, in the fluid states. Furthermore, no evidence for the torsional mode, previously assigned at 91 cm^–1, has been found and calculations have been made which indicate that such a frequency would lead to an un-acceptably high barrier to internal rotation of the asymmetric PC1₂ rotor.Taken from the thesis of J. E. Saunders which has been submitted in partial fulfillment of the Ph.D. degree.     

Optical pulse-shaping for internal cooling of molecules

We consider the use of pulse-shaped broadband femtosecond lasers to optically cool rotational and vibrational degrees of freedom of molecules. Since this approach relies on cooling rotational and vibrational quanta by exciting an electronic transition, it is most easily applicable to molecules with similar ground and excited potential energy surfaces, such that the vibrational state is usually unchanged during electronic relaxation. Compared with schemes that cool rotations by exciting vibrations, this approach achieves internal cooling on the orders-of-magnitude faster electronic decay timescale and is potentially applicable to apolar molecules. For AlH(+), a candidate species, a rate-equation simulation indicates that rovibrational equilibrium should be achievable in 8 μs. In addition, we report laboratory demonstration of optical pulse shaping with sufficient resolution and power for rotational cooling of AlH(+).     

Synthesis and 125Te NMR Spectroscopy of α-Tellurocarbonyl Compounds and Derivatives

The reaction of lithium alkyl-, alkenyl-, alkynyl-, and aryl tellurolates with α-bromocarobonlyl compounds in anhydrous tetrahydrofuan gives the title compounds in yields ranging from 55–92%. The ¹²⁵Te NMR chemical shift range for these compounds is 405–1024 ppm.