Spin Crossover in Nickel(II) Tetraphenylporphyrinate via Forced Axial Coordination at the Air/Water Interface

Molecules

Alexander A. Dmitrienko¹  Andrey P. Kroitor²  Yulia Yu. Enakieva²  Sofiya L. Selektor²  Aslan Yu. Tsivadze²  Alexander V. Shokurov²  Daria S. Kutsybala²  Alexander G. Martynov²  Yulia G. Gorbunova² 

[1] Department of Chemistry, Lomonosov Moscow State University, Leninskie Gory, 1-3, 119991 Moscow, Russia;Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninsky pr. 31-4, 119071 Moscow, Russia;

关键词: nickel porphyrinate;    spin crossover;    ruthenium phthalocyaninate;    supramolecular;    axial coordination;    air/water interface;   

DOI  :  10.3390/molecules26144155

来源: DOAJ

【 摘 要 】

Coordination-induced spin crossover (CISCO) in nickel(II) porphyrinates is an intriguing phenomenon that is interesting from both fundamental and practical standpoints. However, in most cases, realization of this effect requires extensive synthetic protocols or extreme concentrations of extra-ligands. Herein we show that CISCO effect can be prompted for the commonly available nickel(II) tetraphenylporphyrinate, NiTPP, upon deposition of this complex at the air/water interface together with a ruthenium(II) phthalocyaninate, CRPcRu(pyz)₂, bearing two axial pyrazine ligands. The latter was used as a molecular guiderail to align Ni···Ru···Ni metal centers for pyrazine coordination upon lateral compression of the system, which helps bring the two macrocycles closer together and forces the formation of Ni–pyz bonds. The fact of Ni(II) porphyrinate switching from low- to high-spin state upon acquiring additional ligands can be conveniently observed in situ via reflection-absorption UV-vis spectroscopy. The reversible nature of this interaction allows for dissociation of Ni–pyz bonds, and thus, change of nickel cation spin state, upon expansion of the monolayer.

【 授权许可】

Unknown