Structure of the lowest triplet states of poly-α-methylstyryl sodium.: Ab initio calculations

被引：0

作者：

Kalninsh, KK ^{[1
]}

Podolskii, AF ^{[1
]}

机构：

[1] Russian Acad Sci, Inst High Mol Cpds, St Petersburg 196140, Russia

来源：

JOURNAL OF STRUCTURAL CHEMISTRY | 2000年 / 41卷 / 04期

关键词：

Triplet State; Monomer Unit; Charge Transfer State; Triplet Energy; Spin Density Distribution;

D O I：

10.1007/BF02683917

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Ab initio optimisation of a poly-alpha -methylstyryl sodium (PMSNa) fragment consisting of two cis units yields a triplet state energy which is close to the ground state energy. A new mechanism is proposed for depolymerization of "living" polymers, which implies that nit elementary step involves excitation to the low-lying triplet state with a charge transfer and with further bond cleavage. In the reaction structure, electronic excitation occurs with a minor (similar to0.5 Angstrom) displacement of the Na+ cation between the last and the last but one monomer units. The reversible polymerization/depolymerization reaction of PMSNa in THF was studied experimentally. The experimental (5.6 kcal/mole) and calculated (7.3 kcal/mole) polymerization enthalpies are in reasonable agreement.

引用

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页码：572 / 578

页数：7

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