Multimetallic coordination clusters offer significant potential for exhibiting unique structural forms and functional behaviour driven by site-selective metal-ion embedment and the ability to combine specific sets of ...Multimetallic coordination clusters offer significant potential for exhibiting unique structural forms and functional behaviour driven by site-selective metal-ion embedment and the ability to combine specific sets of metal ions within the coordination skeleton.In this work,we present{Fe^(Ⅱ)xMn^(Ⅱ)9x[W^(V)(CN)_(8)]_(6)(MeOH)_(24)}·nMeOH(x=2–7(2–7);n=15,18),an FexMn9−xW6 cyanido-bridged cluster series combining(i)Fe(^(Ⅱ))cations and cyanido-bridged Fe(^(Ⅱ))–W(V)pairs as components,ensuring spin-crossover(SCO)and electron-transfer(ET)switchable behaviour,respectively,and(ii)6-coordinate complexes of Mn(^(Ⅱ)),forming a large cation matrix due to their exceptionally long bonds.On cooling from RT,2–4 revealed a complete^(HS)Fe^(Ⅱ)→LSFe^(Ⅱ)SCO transition at the central[Fe(μ-NC)6]moieties below 200 K.In contrast,5–7 exhibited^(HS)Fe^(Ⅱ)WV→^(HS)Fe^(Ⅱ)IWIV ET with thermal hysteresis(6,7)near 200 K,triggered by SCO at higher temperatures.The reversible spin or valence state changes are coupled with structural transitions and are tuneable with the 3d metal ion composition,as evidenced by comprehensive temperature-dependent data involving SCXRD,PXRD,and SQUID measurements,IR spectroscopy,and 57Fe Mössbauer spectroscopy.The observed switchable behavior is discussed regarding the significant matrix effects of Mn(^(Ⅱ))and the degree of electronic density delocalization along the Fe–W subnetworks of the cyanido-bridged framework.This work significantly expands the switchable 15-nuclear trimetallic sixcapped body-centered cubic cluster library.展开更多
基金National Science Centre(Poland)grant UMO-2014/14/E/ST5/00357 and grant UMO-2019/35/B/ST5/01481(R.P.)funded by the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program(Contract POIG.02.01.00-12-023/08)funded by the Polish Ministry of Science and Higher Education in the framework of the Large Research Infrastructure Fund(Decision 6350/IA/158/2013.1).
文摘Multimetallic coordination clusters offer significant potential for exhibiting unique structural forms and functional behaviour driven by site-selective metal-ion embedment and the ability to combine specific sets of metal ions within the coordination skeleton.In this work,we present{Fe^(Ⅱ)xMn^(Ⅱ)9x[W^(V)(CN)_(8)]_(6)(MeOH)_(24)}·nMeOH(x=2–7(2–7);n=15,18),an FexMn9−xW6 cyanido-bridged cluster series combining(i)Fe(^(Ⅱ))cations and cyanido-bridged Fe(^(Ⅱ))–W(V)pairs as components,ensuring spin-crossover(SCO)and electron-transfer(ET)switchable behaviour,respectively,and(ii)6-coordinate complexes of Mn(^(Ⅱ)),forming a large cation matrix due to their exceptionally long bonds.On cooling from RT,2–4 revealed a complete^(HS)Fe^(Ⅱ)→LSFe^(Ⅱ)SCO transition at the central[Fe(μ-NC)6]moieties below 200 K.In contrast,5–7 exhibited^(HS)Fe^(Ⅱ)WV→^(HS)Fe^(Ⅱ)IWIV ET with thermal hysteresis(6,7)near 200 K,triggered by SCO at higher temperatures.The reversible spin or valence state changes are coupled with structural transitions and are tuneable with the 3d metal ion composition,as evidenced by comprehensive temperature-dependent data involving SCXRD,PXRD,and SQUID measurements,IR spectroscopy,and 57Fe Mössbauer spectroscopy.The observed switchable behavior is discussed regarding the significant matrix effects of Mn(^(Ⅱ))and the degree of electronic density delocalization along the Fe–W subnetworks of the cyanido-bridged framework.This work significantly expands the switchable 15-nuclear trimetallic sixcapped body-centered cubic cluster library.
