【摘要】 本文利用脉冲激光溅射-超声分子束载带离子源在气相中产生了HC_2nO⁺（n=3～6）正离子.通过对贴附CO的络合物离子的红外光解离光谱实验获得了HC_2nO⁺正离子在1600～3500 cm^-1范围内的红外光谱.通过比较实验光谱和理论模拟光谱确定了HC_2nO⁺正离子具有端接氢和氧的直线型碳链衍生物结构,基态为三重态,单重态比三重基态能量高10～15 kcal/mol.成键分析表明HC_2nO⁺中的碳链具有连烯的结构特征.更多还原

【Abstract】 The carbon chain cations, HC_2nO⁺（n=3-6） are produced via a pulsed laser vaporization supersonic expansion ion source in the gas phase. Their infrared spectra are measured via mass-selected infrared photodissociation spectroscopy of the CO "tagged" [HC_2nO·CO]⁺ cation complexes in 1600-3500 cm^-1 frequency range. The geometric and electronic structures of the [HC_2nO·CO]⁺ complexes and the core HC_2nO⁺（n=3-6） cations are determined with the aid of density functional theory calculations. These HC_2nO⁺（n=3-6） ions are identified to be linear carbon chain derivatives terminally capped by hydrogen and oxygen. The triplet ground states are 10-15 kcal/mol lower in energy than the singlet states, indicating cumulene-like carbon chain structures.更多还原