Steady- State and Pseudo-Steady-State Photocrystallographic Studies on Linkage Isomers of [Ni( Et4dien)(n2-O,ON)(n1-NO2)]: Identification of a New Linkage Isomer

被引：50

作者：

Hatcher, Lauren E. ^{[1
]}

Christensen, Jeppe ^{[2
]}

Hamilton, Michelle L. ^{[2
]}

Trincao, Jose ^{[2
]}

Allan, David R. ^{[3
]}

Warren, Mark R. ^{[3
]}

Clarke, Ian P. ^{[4
]}

Towrie, Michael ^{[4
]}

Fuertes, Sara ^{[1
]}

Wilson, Charles C. ^{[1
]}

Woodall, Christopher H. ^{[1
]}

Raithby, Paul R. ^{[1
,2
]}

机构：

[1] Univ Bath, Dept Chem, Bath BA2 7AY, Avon, England

[2] Rutherford Appleton Lab, Didcot OX11 0FA, Oxon, England

[3] Diamond Light Source Ltd, Didcot OX11 0DE, Oxon, England

[4] STFC Rutherford Appleton Lab, Cent Laser Facil, Didcot OX11 0QX, Oxon, England

来源：

CHEMISTRY-A EUROPEAN JOURNAL | 2014年 / 20卷 / 11期

基金：

英国工程与自然科学研究理事会;

关键词：

linkage isomers; metastable states; nitro complexes; photocrystallography; solid-state kinetics; TRANS-CINNAMIC ACID; SOLID-STATE; SINGLE-CRYSTAL; PHOTODIMERIZATION; COMPLEXES; KINETICS; NICKEL(II); NITRO;

D O I：

10.1002/chem.201304172

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

At temperatures below 150K, the photoactivated metastable endo-nitrito linkage isomer [Ni(Et(4)dien)((2)-O,ON)((1)-ONO)] (Et(4)dien=N,N,N,N-tetraethyldiethylenetriamine) can be generated with 100% conversion from the ground state nitro-((1)-NO2) isomer on irradiation with 500nm light, in the single crystal by steady-state photocrystallographic techniques. Kinetic studies show the system is no longer metastable above 150K, decaying back to the ground state nitro-((1)-NO2) arrangement over several hours at 150K. Variable-temperature kinetic measurements in the range of 150-160K show that the rate of endo-nitrito decay is highly dependent on temperature, and an activation energy of E-act=+48.6(4)kJmol(-1) is calculated for the decay process. Pseudo-steady-state experiments, where the crystal is continually pumped by the light source for the duration of the X-ray experiment, show the production of a previously unobserved, exo-nitrito-((1)-ONO) linkage isomer only at temperatures close to the metastable limit (ca. 140-190K). This exo isomer is considered to be a transient excited-state species, as it is only observed in data collected by pseudo-steady-state methods.

引用

页码：3128 / 3134

页数：7

共 38 条

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