Synthesis, crystal structures and semiconducting properties of new hexacyanidometallates. Issue 13 (7th March 2023)

• Record Type: Journal Article
• Authors: Qiao, Xianji; Qiu, Yi; Xin, Junjie; Chen, Da; Ma, Zili; Corkett, Alex J.; Cai, Guohong; Cai, Guanqun; Qu, Shangqing; Wang, YuChao; Zhu, Zhenyu; Gao, Yiman; Wang, Zhigang; Dronskowski, Richard; Li, Guobao; Sun, Junliang
• Is Part Of: Dalton transactions. Volume 52:Issue 13(2023)
• Page Start: 3971
• Page End: 3980
• Publication Date: 2023-03-07
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d3dt00384a
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : New hexacyanidometallates with the formula A2 [MFe(CN)6 ]· x H2 O (A = Na, K; M = Mg, Ca, Sr and Ba) were determined to adopt unexpectedly low-symmetric structures which has been demonstrated as n-type semiconductors. Abstract : We describe the synthesis, crystal structure and semiconducting properties of a number of hexacyanidometallates with the formula A2 [MFe(CN)6 ]· x H2 O (A = Na, K; M = Mg, Ca, Sr and Ba). All crystal structures were studied via single-crystal or powder X-ray diffraction. The unexpectedly low-symmetric structures in these ferrocyanides are described and contrasted with analogous transition-metal compounds which have been reported to be strictly or nearly cubic. The amount of crystal water in the structure for powder samples was determined by the thermogravimetric analysis (TGA), supported by IR and Raman spectroscopy. Electronic-structure calculations of K2 [MgFe(CN)6 ] and K2 [CaFe(CN)6 ] are compared with experimental UV-Vis measurements. The large band gaps by advanced theory indicate that the smaller experimental band gaps are due to surface effects of impurity states. Mott–Schottky curves of K2 [MgFe(CN)6 ], K2 [CaFe(CN)6 ] and K2 [BaFe(CN)6 ]·3H2 O exhibit positive slopes, which characterizes these compounds as n-type semiconductors.