Octa-coordination in complexes of lanthanides with N2 confirmed by matrix-isolation IR spectroscopy and DFT calculations

Although the existence of binary dinitrogen-lanthanide metal complexes was established some twenty years ago, particularly the controversy about the highest possible coordination number (hexa- or octa-coordinated) prevails. In this study lanthanide (Ln) dinitrogen complexes, synthesized in neat dinitrogen cryogenic matrices, were investigated by infrared and UV-visible spectroscopy. Surprisingly, only some metals react directly with N2 to yield compound, while in most cases metal atoms are observed in the neat dinitrogen matrix – which react upon photoexcitation. Strong support for assignments were achieved by extensive quantum chemical calculations using the BP86 exchange-correlation DFT functional in conjunction with relativistic pseudopotentials and valence triple-zeta basis sets. The results were analysed with respect to experimental and literature data. Our joint experimental-theoretical analysis confirmed the formation of octa-coordinated end-on Ln(NN)8 complexes in cryogenic matrices.

KOVACS Attila;  KLOTZBÜCHER Werner; 

2022-10-05

ELSEVIER

JRC129995

0022-2860 (online),   

https://www.sciencedirect.com/science/article/pii/S0022286022018737,    https://publications.jrc.ec.europa.eu/repository/handle/JRC129995,   

10.1016/j.molstruc.2022.134222 (online),