Meizyte Gabriele, Brown Rachael H, Brewer Edward I, Watson Peter D, Mackenzie Stuart R
Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford, United Kingdom, OX1 3QZ.
J Phys Chem A. 2023 Nov 9;127(44):9220-9228. doi: 10.1021/acs.jpca.3c05078. Epub 2023 Oct 31.
In this study, mixed carbonyl and nitrous oxide complexes with Rh were studied by mass-selective infrared photodissociation spectroscopy in a molecular beam. The infrared spectra, recorded in the region of the CO and NO N═N stretches, were assigned and interpreted with the aid of simulated spectra of low-energy structural isomers. Clear evidence of an inner coordination shell of four ligands is observed. The observed vibrational structure can be understood on the basis of local mode vibrations in the two ligands. However, there is also evidence of multiple low-lying isomers and cooperative binding effects between the two ligands. In particular, σ donation from directly coordinated nitrous oxide ligands drives more classical carbonyl bonding than has been observed in pure carbonyl complexes. The observed fragmentation branching ratios following resonant infrared absorption are explained by simple statistical and energetic arguments, providing a contrast with those of equivalent Au complexes.
在本研究中，利用分子束中的质量选择红外光解离光谱对铑的混合羰基和一氧化二氮配合物进行了研究。在CO和NO N═N伸缩区域记录的红外光谱，借助低能量结构异构体的模拟光谱进行了归属和解释。观察到了由四个配体构成的内配位层的明确证据。所观察到的振动结构可以基于两个配体中的局域模式振动来理解。然而，也有证据表明存在多个低能异构体以及两个配体之间的协同结合效应。特别是，直接配位的一氧化二氮配体的σ给予作用比在纯羰基配合物中观察到的更能驱动经典的羰基键合。通过简单的统计和能量论据解释了共振红外吸收后的观察到的碎片分支比，这与等效金配合物的情况形成了对比。
