We report the generation, spectroscopic characterization, and computational analysis of the first free (non-stabilized) organometallic bismuthinidene, BiMe. The title compound was generated in situ from BiMe3 by controlled homolytic Bi−C...

Matrix isolation infrared spectroscopy has been used to investigate intermolecular interactions in a series of binary O-H⋯O hydrogen bonded phenol-water complexes where water is the common acceptor. The interaction at the binding site has been tuned by incorporating multiple fluorine substitutions at different aromatic ring sites of the phenol moiety. The spectral effects for the aforesaid chemical changes are manifested in the infrared spectra of the complexes as systematic increase in spectral shift of the phenolic O-H stretching fundamental (ΔνO-H). While νO-H bands of the monomers of all the fluorophenols appear within a very narrow frequency range, the increase in ΔνO-H of the complexes from phenol to pentafluorophenol is very large, nearly 90%. The observed values of ΔνO-H do not show a linear correlation with the total binding energies (ΔEb) of the complexes, expected according to Badger-Bauer rule. However, in the same ΔνO-H vs ΔEb plot, nice linear correlations are revealed if the complexes of ortho-fluorophenols are treated separately from their meta/para-substituted analogues. The observations imply that in spite of having the same binding site (O-H⋯O) and the same chemical identities (phenolic), the complexes of ortho and non-ortho fluorophenols do not belong, from the viewpoint of detailed molecular interactions, to a homologous series. Linear correlations of ΔνO-H are, however, observed with respect to the electrostatic component of ΔEb as well as the quantum mechanical charge transfer interaction energy (ECT). From quantitative viewpoint, the latter correlation along with the associated electronic structure parameters appears more satisfactory. It has also been noted that the observed ΔνO-H values of the complexes display a linear relationship with the aqueous phase pKa values of the respective phenol derivatives.

UV photodissociation of benzoyl chloride, Ph−CO−Cl, is associated with the loss of a chlorine atom. Here we excite benzoyl chloride to the S 1 , S 2 , and S 3 excited states at 237, 253, 265, and 279.6 nm and detect the Cl photofragment by [1 + 1′] photoionization using 118.9 nm VUV radiation. The translational energy distribution of the Cl atom is measured by velocity map ion imaging. An isotropic image and a unimodal translational energy distribution are observed at all dissociation wavelengths, and a fraction of 18−20% of the excess energy is released into translation. The results indicate a dissociation that predominately proceeds from the vibrationally hot S 0 ground state, although the observed translational energy release deviates significantly from a prior distribution. However, the impulsive model does also not represent the translational energy release. As a Cl/Cl* branching ratio of 9:1 or more is observed in one-color experiments at 235 nm, we conclude that direct dissociation from excited electronic states contributes only to a minor extent.

We have investigated the photoionization of ammonia borane (AB) and determined adiabatic ionization energy to be 9.26 � 0.03 eV for the X + 2 E ! X 1 A 1 transition. Although the threshold photoelectron spectrum appears at first glance to be similar to the one of the isosteric ethane, the electronic situation differs markedly, due to different orbital energies. In addition, an appearance energy AE 0K -(NH 3 BH 3 , NH 3 BH 2 + ) = 10.00 � 0.03 eV has been determined, corresponding to the loss of a hydrogen atom at the BH 3 -site. From the data, a 0 K bond dissociation energy for the BÀ H bond in the cation of 71.5 � 3 kJ mol À 1 was derived, whereas the one in the neutral compound has been estimated to be 419 � 10 kJ mol À 1 .