氧原子簇O_x^y(x=2～6,y=-2～2)的结构、能学与光谱性质  

Geometries, Energetics and Spectroscopic Properties of Oxygen Clusters O_x^y (x=2~6, y=-2~2)

作　　者：易军[1] 陈鸿博[1] 魏光[1] 林银钟[1] 廖代伟[1] 

机构地区：[1]厦门大学物理化学研究所

出　　处：《Chinese Journal of Chemical Physics》2001年第1期65-74,共10页化学物理学报（英文）

基　　金：国家自然科学基金!资助项目 ( 2 97730 37)&&

摘　　要：在B3LYP/ 6- 311G(d ,p)水平上 ,对氧原子簇Oxy(x =2～ 6,y =- 2～ 2 )的结构、能学与光谱性质进行了量子化学从头计算 ,对 3O2 和 2 O2 +的基态和激发态进行了CASSCF计算。结果表明 ,氧分子及其离子的体系总能量大小为 3O2 ( 3Σg- ) <2 O2 - ( 2 Πgi) <1O2 ( 1Δg) <1O2 - 2 ( 1Σg+)<2 O2 +( 2 Πg) <1O2 +2 ( 1Σg+)。活性的二重态氧分子负离子2 O2 - ( 2 Πgi)在相对能量上只比三重态的中性氧分子 3O2 ( 3Σg- )高 2 8kJ/mol。对于弯曲型 (Structure -I)的臭氧分子 (O3)及其离子 ,其体系总能量相对次序为 2O3- ( 2 B1) <1O3( 1A1) <3O3( 3B2 ) <1O3- 2 ( 1A1) <2 O3+( 2 A1)。氧四聚体 (O4 )及其离子的体系总能量相对大小为 2O4 - (Cs 弯曲型 ,2A′) <2 O4 - (C2v面心三角型 ,2 A2 ) <2 O4 - (D∞h直线型 ,2Σg) <1O4 (Cs 弯曲型 ,1A′) <1O4 (D∞h直线型 ,1Σg) <1O4 (D4h正方型 ,1A1g) <1O4 (C2v面心三角型 ,1A1) <2 O4 - (D4h正方型 ,1A1g) <2 O4 +(D∞h直线型 ,2Σg) <2 O4 +(Cs 弯曲型 ,1A′)。相对能量最低的氧四聚体物种是呈椅形的带一个负电荷的负离子 2 O4 - (Cs 弯曲型 ,2 A′) ,其特征振动频率应出现在 1179和 134 9cm- 1。共面三角双锥型的 1O5(C2v,1A1)相对能量最低 ,其与A字型The geometries, energetics and spectroscopic properties of oxygen clusters, O x y (x=2~6, y=-2~2), were investigated at the B3LYP/6-311G (d, p) level. The CASSCF calculations were carried out for the ground and excited states of 3O 2 and 2O 2 +. The total energy is 3O 2( 3Σ g -)< 2O 2 -( 2Π gi )< 1O 2( 1Δ g)< 1O 2 -2 ( 1Σ g +)< 2O 2 +( 2Π g)< 1O 2 +2 ( 1Σ g +). The relative energy of the active doublet anion of oxygen molecule, 2O 2 -( 2Π gi ), is only 28 kJ/mol higher than the triplet neutral oxygen molecule, 3O 2( 3Σ g -). The calculated O-O vibrational frequencies all are in good agreement with the experimental values. They are 1577 (1580), 1139 (1090), 1563 (1484), 627 (615~545) and 1993 (1905) cm -1 , where the O-O vibrational frequency values in parentheses are experimental values, for 3O 2( 3Σ g -), 2O 2 -( 2Π gi ), 1O 2( 1Δ g), 1O 2 -2 ( 1Σ g +) and 2O 2 +( 2Π g), respectively. Moreover, the O-O vibrational frequency of 1O 2 +2 ( 1Σ g +) was computed as 2368 cm -1 which has not been reported before at both experimental and theoretical levels. Both bent and linear geometries of O 3 were studied. The bent-types of O 3 are more favorable than the linear-type in energy. Three types of structure for oxygen trimers are calculated at the B3LYP/6-311G (d, p) level. They are the structure-I with an obtuse angle of O-O-O, the structure-II with an acute angle of O-O-O, and the structure-III of linear type. For a bent-type structure of O 3 species (structure-I), the total enegy is 2O 3 -( 2B 1)< 1O 3( 1A 1)< 3O 3( 3B 2)< 1O 3 -2 ( 1A 1)< 2O 3 +( 2A 1). The optimization of geometry at B3LYP/6-311G (d, p) level indicated that the species of 2O 3 -( 2B 1) with 1.3573 of O-O bond length and 115.6584 o of O-O-O bond anger is the ground state of O 3. The total energy of O 4 species and their ions is 2O 4 -(C s, 2A′, bend-type)< 2O 4 -(C

关 键 词：ABINITIO 光谱性质 结构 能学 氧原子簇 

分 类 号：O641[理学—物理化学]