Infrared spectroscopy of Be(CO₂)₄⁺in the gas phase: electron transfer and C–C coupling of CO₂

Abstract

Beryllium-carbon dioxide cation complexes Be(CO2)n+ are produced by a laser vaporization-supersonic expansion ion source in the gas phase. Mass-selected infrared photodissociation spectroscopy supplemented by theoretical calculations confirms that Be(CO2)4+ is...

Infrared Spectroscopy of [M(CO2)n]+ (M = Ca, Sr, and Ba; n = 1–4) in the Gas Phase: Solvation-Induced Electron Transfer and Activation of CO2

“…50 The reduction of carbon dioxide to metal oxalate species has been reported in the alkali metal and bismuth anionic complexes as well as alkaline earth metal neutral and cationic complexes. 20,23,51,52 The experimental IR spectrum for the n = 3 complex (Figure 1) is quite similar to the n = 2 complex except that no shoulder is observed in the high frequency region (2300−2400 cm −1 ) for the n = 3 complex and that more bands are observed in the low frequency 1200−1600 cm −1 region. The observation of only one band at 2365 cm −1 in the high frequency region suggests the involvement of only one isomer.…”

“…The bidentate η 2 -C, O coordination mode has been observed in the V­(CO 2 ) n + n ≥ 7 clusters with characteristic stretching vibration around 1800 cm –1 . The reduction of carbon dioxide to metal oxalate species has been reported in the alkali metal and bismuth anionic complexes as well as alkaline earth metal neutral and cationic complexes. ,,, …”

“…The first isomer involves a bent CO 2 – ligand that is bound in a monodentate η 1 -O coordination mode. Another isomer has a metal oxalate-type C 2 O 4 – moiety with a C–C hemibond . Solvation-induced metal cation → carbon dioxide electron transfer with the formation of a bidentate η 2 -O, O coordinated CO 2 – moiety was reported on the [Mg­(H 2 O) n (CO 2 )] + complexes with n ≥ 4 …”

“…Atomically dispersed magnesium and calcium were found to be active sites for electroreduction of CO 2 to CO. , Alkaline earth metal hydrides can activate carbon dioxide to the HM­(O 2 CH) and (MH 2 )­(HCOOH) complexes (M = Sr and Ba) . Thus, the coordination and activation of carbon dioxide by alkaline earth metal atoms and ions have been extensively studied. − Spectroscopic studies in cryogenic noble gas matrices indicated that the beryllium atom is able to insert into the C–O bond of carbon dioxide in forming the inserted OBeCO complex. , In contrast, the calcium atom reacts with carbon dioxide, forming a charge-transferred complex CaCO 2 , in which the strongly bent CO 2 – ligand is side-on coordinated to the calcium center in an η 2 -O, O manner . The ground-state alkaline earth metal atoms react with two carbon dioxide molecules to produce the oxalate complexes MC 2 O 4 and the carbonate–carbonyl complexes OCMCO 3 (M = Ca, Sr, and Ba) spontaneously on annealing .…”

Conversion of Carbon Dioxide into a Series of CBxOy– Compounds Mediated by LaB3,4O2– Anions: Synergy of the Electron Transfer and Lewis Pair Mechanisms to Construct B–C Bonds

“…The C atom changes from a positive charge in the free CO 2 molecule to a negative charge in the product, and the charge of the B2 atom changes in the opposite way. In both gas-phase ,,− and condensed-phase − systems, metal sites consisting of one or more metal atoms are usually required to donate electrons to activate CO 2 . Distinct from this common mode, we find that the synergy of the electron transfer and Lewis acid–base pair mechanisms, that is, boron–boron Lewis pairs (LPs), is responsible for the complete cleavage of the C–O bond.…”