Time-sliced velocity map ion imaging(VMI)experiments were performed to investigate the photodissociation of H_(2)S^(+)X^(2)B_(1),via the excitation to the A^(2)A_(1)(0,11,0)state.Experimental images of the S^(+)(^(4)Su)products were recorded near 349.60 nm for the K=1 band,and near 344.30 nm for the K=2 band.The derived product total kinetic energy release(TKER)spectra exhibit partially rotationally resolved structures corresponding to the H_(2)(X^(1)∑_(g)^(+))co-products.The observed product state and angular distributions both exhibit sensitive dependence on the photolysis wavelength at near 349.60 nm and 344.30 nm.These phenomena indicate the underlying rich dynamic details and the role of the rotational excitation of H_(2)S^(+).
Yuxin TanYaling WangChang LuoDaofu YuanXiaoguo ZhouXingan WangXueming Yang
SiO is a wide-spread molecule found in interstellar space.Previous research has primarily focused on its spectroscopy,while its photodissociation dynamics is elusive to study due to high dissociation energy.Using time-sliced ion velocity imaging technique,we observed the Si(^(3)P)+O(^(3)P)photodissociation process resulting from the excitation of highly vibrationally excited SiO(X^(1)Σ^(+),υ=13-18)molecules to the SiO(A^(1)Π,E^(1)Σ^(+))states at 193 nm.The vibrationally excited SiO molecules were generated via laser ablation of silicon rod with the collision of the oxygen molecular beam acting as carrier gas and reaction gas.The bond dissociation energy D_(e)(Si-O)is determined to be 67253±110 cm^(-1)(8.34±0.01 eV)based on the kinetic energy distribution spectrum.The SiO photodissociation study has deepened our understanding of the mechanisms of silicon chemistry for silica-rich rocky meteors as they burn in the Earth's atmosphere,and the dissociation of SiO from ablation of meteoroids following ultraviolet photon absorption.
Yujie MaFangfang LiDong YanAng XuTi ZhouJiaxing LiuFengyan Wang
