Zinc and Cadmium Dihydroxide Molecules:  Matrix Infrared Spectra and Theoretical Calculations

Abstract

Laser-ablated zinc and cadmium atoms were mixed uniformly with H2 and O2 in excess argon or neon and with O2 in pure hydrogen or deuterium during deposition at 8 or 4 K. UV irradiation excites metal atoms to insert into O2 producing OMO molecules (M = Zn, Cd), which react further with H2 to give the metal hydroxides M(OH)2 and HMOH. The M(OH)2 molecules were identified through O-H and M-O stretching modes with appropriate HD, D2, (16,18)O2, and (18)O2 isotopic shifts. The HMOH molecules were characterized by O-H, M-H, and M-O stretching modes and an M-O-H bending mode, which were particularly strong in pure H2/D2. Analogous Zn and Cd atom reactions with H2O2 in excess argon produced the same M(OH)2 absorptions. Density functional theory and MP2 calculations reproduce the IR spectra of these molecules. The bonding of Group 12 metal dihydroxides and comparison to Group 2 dihydroxides are discussed. Although the Group 12 dihydroxide O-H stretching frequencies are lower, calculated charges show that the Group 2 dihydroxide molecules are more ionic.

Infrared spectrum and structure of the gold dihydroxide molecule

“…Fig. 1 18 O 2 shows four bands; namely the 16 O 2 band at 3565.9 cm 21 , the 18 O 2 band at 3555.1 cm 21 , and new 3570.8 and 3557.5 cm 21 bands in a 1 : 3 ratio. The last two are due to coupled 16 OH and 18 O 2 .…”

“…Complementary experiments were performed with H 2 and O 2 mixtures so that 18 O 2 can be incorporated into the product molecules. 20,21 Theoretically, the structure and vibrational frequencies of the Au(OH) 2 molecule were calculated using methods employed for gold hydrides. 4,22 Relativistic effects were included in the SDD pseudopotential for gold.…”

Matrix Isolation ESR and Theoretical Study of ZnN

“…For ZnH, ZnP, and ZnCH 3 , the Zn-67 hyperfine coupling was observed. The small zinc molecules, ZnOH, , ZnCN, ZnCCH, and HZnCH 3 , have all been studied by rotational spectroscopy in the gas phase, whereas ZnO, OZnO, ZnH 2 , ZnOH, HZnOH, and Zn­(OH) 2 and ZnCH 2 , HZnCH, HZnCH 3 , , and ZnNO 2 have also been studied using matrix isolation IR spectroscopy and Zn 2 , ZnHg, MgZn, and CdZn and ZnD 2 and HZnCH 3 have been studied in matrices with UV and VUV electronic spectroscopy. Additionally, the AlZn molecule was studied by resonant two-photon ionization (R2PI) spectroscopy and ZnCH 3 and ZnC 2 H 5 , Zn-pyrrolyl, Zn-monomethylcyclopentadienyl, and Zn-cyclopentadienyl molecules were studied in the gas phase via laser-induced fluorescence.…”

Properties of Lanthanide Hydroxide Molecules Produced in Reactions of Lanthanide Atoms with H2O2 and H2 + O2 Mixtures: Roles of the +I, +II, +III, and +IV Oxidation States

“…Another source of oxidative addition products is the reaction with hydrogen peroxide molecules, which has become straightforward through the use of a urea–hydrogen peroxide complex as a source of H 2 O 2 molecules at room temperature. − (In ref , the captions for Figures 8 and 9 should state La instead of Y.) Owing to the relatively weak O–O bond (50 kcal/mol) in H 2 O 2 , metal atom reactions to form M­(OH) 2 are highly exothermic.…”