The Ti2H2 molecule: terminal or bridging hydrogens ?
The Ti2H2 molecule: terminal or bridging hydrogens ?
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Ti2H2 分子：末端或桥接氢 ?
DOI：
10.1007/s002140000115
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发表时间：
2000
影响因子：
1.7
通讯作者：
I. Pápai
中科院分区：
文献类型：
--
作者：
I. Pápai
摘要。对Ti2H2进行的密度泛函计算表明，几种结构相对于Ti2+H2是热力学稳定的。发现Ti2H2的基态为3B1，它包含两个非平面C2v排列的氢桥。桥接结构的1A1态和其他三重态每摩尔只比基态高几千卡。与Ti类似的乙炔对应的1Σg+态在能量上不如桥接结构有利，但相对于Ti2+H2它仍然是结合的。也给出了Ti2H分子的结果。由于形成了强共价的Ti-H键，桥接异构体和末端异构体都非常稳定。Ti2H2和Ti2H异构体的谐波振动频率和红外强度与Tix/H2的基体分离红外光谱的比较表明，这些分子可能是在低温反应中产生的。
Abstract. Density functional calculations carried out for Ti2H2 show that several structures are thermodynamically stable with respect to Ti2+H2. The ground state of Ti2H2 is found to be 3B1 and it involves two hydrogen bridges in a nonplanar C2v arrangement. The 1A1 state and other triplet states of the bridging structure are only a few kilocalories per mole above the ground state. The 1Σg+ state, which corresponds to the Ti analogue of acetylene, is energetically less favored than the bridging structure but it is still bound relative to Ti2+H2. Results are also presented for the Ti2H molecule. Both bridging and terminal isomers are found to be very stable due to the formation of strong covalent Ti-H bonds. A comparison of the calculated harmonic vibrational frequencies and IR intensities of Ti2H2 and Ti2H isomers with the spectra from matrix isolation IR studies on Tix/H2 indicates that these molecules may have been produced in low-temperature reactions.