Robert T. Arlinghaus

Infrared spectra of OC–HX hydrogen‐bonded complexes in solid argon

The hydrogen‐bonded complexes OC–HX (X=F, Cl, Br) has been prepared by condensing Ar/HX and Ar/CO reagent mixtures at 12 K. FTIR spectra of the complexes are characterized by strong H–X absorptions (νs) displaced below the isolated HX fundamental, strong C–O absorptions displaced above the isolated CO fundamental, and sharp degenerate librational modes (νl) in the far infrared. Observation of a single degenerate νl mode indicates linear structures for the complexes. The displacements Δνs and ΔνCO for the complexes decrease in magnitude in the series HF≳HCl≳HBr in direct relationship with the trend in hydrogen bonding strength for the hydrohalic acids.

FTIR observation of the N2‐‐‐HF complex in solid argon

Sharp absorptions at 3881.5 and 262 cm−1 in argon matrices containing HF are shown to depend upon N2. Substitution with DF indicates assignments to the νs and νl modes of the linear N2‐‐‐HF complex.

Infrared spectra of the PH3, AsH3, and SbH3‐‐HX hydrogen bonded complexes in solid argon

Infrared spectra have been observed for several group V base–HX (X=F, Cl) hydrogen bonded complexes formed by codeposition of Ar/base and Ar/HX samples. The decrease in displacement of the H–X stretching fundamentals for the heavier bases parallels a similar decrease in base proton affinities, indicating decreasing hydrogen bond strengths. A single, sharp degenerate librational mode was observed, which indicates C3v structures for the complexes. The decrease in librational fundamentals observed in the order PH3>AsH3>SbH3 and decreasing 2νl/νl ratios indicate increasing anharmonicity and less rigid structures for the heavier complexes. Polarization of the phosphine lone pair and concentration of the P‐H bonding electrons is suggested by blue‐shifted νc3 and νc1 complex modes. OFF

Infrared spectrum of the CO2–HCl complex in solid argon at 12 K

Co‐condensation of CO2 and HCl in excess argon at 12 K produced the CO2–HCl hydrogen‐bonded complex. Small shifts in the νs and ν3c modes, the low νl fundamental, and a very weak infrared Fermi doublet indicate a weakly bound complex. The more strongly bound CO2–HF and C 18O2–HF complexes gave more intense infrared Fermi doublets. The infrared intensity ratio ν3/ν1 is 200/1 for the CO2–HF complex demonstrating that the HF ligand induces finite electrical asymmetry in the CO2 submolecule.

Matrix infrared spectra of HF complexes with N2O, OCS and CS2

Abstract Solid neon/N 2 O/HF mixtures reveal infrared spectra of the N 2 O---HF and ON 2 ---HF structural isomers of the hydrogen bonded complexes observed in nozzle beam expansions. Solid argon/OCS/HF and argon/CS 2 /HF mixtures yield spectra of the SCO---HF and CS 2 ---HF complexes and provide several interesting comparisons with CO 2 ---HF complex spectra.

Absorption spectra of substituted biphenyl and related cations in solid argon and a comparison with photoelectron spectra

One-photon and two-photon matrix photoionization experiments have been performed with substituted biphenyls, fluorene and 9,10-dihydrophenanthrene. Absorption spectra in the red region correlate with photoelectron spectra for a π3→π6 transition and indicate a relaxation of the dihedral angle upon ionization. Sharp ultraviolet absorption spectra are assigned to π→π* transitions for the matrix-isolated cations.

Absorption Spectra of Diphenylacetylene and 1,4-Diphenylbutadiyne Cations in Solid Argon

One and two-photon matrix photoionization techniques have been used to prepare diphenylacetylene and 1,4-diphenylbutadiyne cations. Identification of these cations was confirmed by photoelectron spectra and radiolysis studies. Near-infrared absorption bands for each cation correlate with photoelectron spectra and suggest structural relaxation about the molecular axis on ionization, and strong blue absorptions that do not correlate with photoelectron spectra are probably caused by π → π* transitions.