Manipulation of the molecular spin crossover transition of Fe(H2B(pz)2)2(bipy) by addition of polar molecules. (22nd October 2019)

• Record Type: Journal Article
• Authors: Costa, Paulo S; Hao, Guanhua; N'Diaye, Alpha T; Routaboul, Lucie; Braunstein, Pierre; Zhang, Xin; Zhang, Jian; Ekanayaka, Thilini K; Shi, Qin-Yin; Schlegel, Vicki; Doudin, Bernard; Enders, Axel; Dowben, P A
• Is Part Of: Journal of physics. Volume 32:Number 3(2020)
• Publication Date: 2019-10-22
• Subjects: spin crossover metal organic molecules -- x-ray absorption spectroscopy -- dipolar heteromolecular molecular interactions -- re-entrant transition; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/1361-648X/ab468c
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: The addition of various dipolar molecules is shown to affect the temperature dependence of the spin state occupancy of the much studied spin crossover Fe(II) complex, [Fe{H2 B(pz)2 }2 (bipy)] (pz = pyrazol-1-yl, bipy = 2, 2′-bipyridine). Specifically, the addition of benzimidazole results in a re-entrant spin crossover transition, i.e. the spin state starts in the mostly low spin state, then high spin state occupancy increases, and finally the high spin state occupancy decreases with increasing temperature. This behavior contrasts with that observed when the highly polar p -benzoquinonemonoimine zwitterion C6 H2 (… NH2 )2 (… O)2 was mixed with [Fe{H2 B(pz)2 }2 (bipy)], which resulted in locking [Fe{H2 B(pz)2 }2 (bipy)] largely into a low spin state while addition of the ethyl derivative C6 H2 (… NHC2 H5 )2 (… O)2 did not appear to perturb the spin crossover transition of [Fe{H2 B(pz)2 }2 (bipy)].