title: Photoswitchable CuMoIVand CuMoIVcyanido-bridged molecules.
abstract: The self-assembly of copper(ii) complexes with two Schiff base ligands: L1O= N3and L2 = N4and octacyanidomolybdate(iv) ions yields two discrete molecules of odd nuclearity, namely pentametallic [Cu(L1O)(py)]4[MoIV(CN)8]·14H2O (1), Cu4Mo and trimetallic [Cu(L2)]2[MoIV(CN)8]·9H2O (2), Cu2Mo. Both molecular systems have been characterised structurally and magnetically, revealing a photomagnetic effect. In the case of (1) a metal-to-metal charge transfer (MMCT) mechanism is proposed. The analysis of magnetic interactions in the photogenerated state of (1) assumes the formation of the metastable cluster CuCuIMoVwhere metal centres in MoV-CN-CuIIlinkages are ferromagnetically coupled with J2= 104(3) cm-1. In (2) the increase in the magnetisation is due to the singlet-triplet transition on the MoIVcentre leading to the formation of the metastable CuMo. The presence of the paramagnetic Mo (S = 1) centre linking the CuII(S = 1/2) centres allows for effective ferromagnetic interaction of 3 paramagnetic centres with coupling constant J2= 20.2(7) cm-1.
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland. tomasz.korzeniak@uj.edu.pl barbara.sieklucka@uj.edu.pl.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Korzeniak
authors.forename: Dawid
authors.initials: D
authors.lastname: Pinkowicz
authors.forename: Wojciech
authors.initials: W
authors.lastname: Nitek
authors.forename: Tomasz
authors.initials: T
authors.lastname: Dańko
authors.forename: Robert
authors.initials: R
authors.lastname: Pełka
authors.forename: Barbara
authors.initials: B
authors.lastname: Sieklucka