Inorganic-organic hybrid Cu-dipyridyl semiconducting polymers based on the redox-active cluster [SFe 3 (CO) 9 ] 2- : filling the gap in iron carbonyl chalcogenide polymers

• Published in: Dalton transactions : an international journal of inorganic chemistry 2024-04, Vol.53 (17), p.7303-7314
• Main Authors: Hsu, Ming-Chi, Lin, Ru Yan, Sun, Tzu-Yen, Huang, Yu-Xin, Li, Min-Sian, Li, Yu-Huei, Chen, Hui-Lung, Shieh, Minghuey
• Format: Article
• Language: English
• Subjects: Bonding; Carbonyls; Clusters; Conjugation; Coordination polymers; Density of states; Electrochemistry; Electron transport; Energy gap; Ethane; Iron; Ligands; Photoelectrons; Polymers; Solid state; Spectrum analysis; Two dimensional analysis; X ray absorption; X ray analysis; X ray photoelectron spectroscopy
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d4dt00254g

The construction of sulfur-incorporated cluster-based coordination polymers was limited and underexplored due to the lack of efficient synthetic routes. Herein, we report facile mechanochemical ways toward a new series of SFe (CO) -based dipyridyl-Cu polymers by three-component reactions of [Et N] [SFe (CO) ] ([Et N] [1]) and [Cu(MeCN) ][BF ] with conjugated or conjugation-interrupted dipyridyl ligands, 1,2-bis(4-pyridyl)ethylene (bpee), 1,2-bis(4-pyridyl)ethane (bpea), 4,4'-dipyridyl (dpy), or 1,3-bis(4-pyridyl)propane (bpp), respectively. X-ray analysis showed that bpee-containing 2D polymers demonstrated unique SFe (CO) cluster-armed and cluster-one-armed coordination modes the hypervalent μ -S atom. These S-Fe-Cu polymers could undergo flexible structural transformations with the change of cluster bonding modes by grinding with stoichiometric amounts of dipyridyls or 1/[Cu(MeCN) ] . They exhibited semiconducting behaviors with low energy gaps of 1.55-1.79 eV and good electrical conductivities of 3.26 × 10 -1.48 × 10 S cm , tuned by the SFe (CO) cluster bonding modes accompanied by secondary interactions in the solid state. The electron transport efficiency of these polymers was further elucidated by solid-state packing, X-ray photoelectron spectroscopy (XPS), X-ray absorption near-edge spectroscopy (XANES), density of states (DOS), and crystal orbital Hamilton population (COHP) analysis. Finally, the solid-state electrochemistry of these polymers demonstrated redox-active behaviors with cathodically-shifted patterns compared to that of [Et N] [1], showing that their efficient electron communication was effectively enhanced by introducing 1 and dipyridyls as hybrid ligands into Cu -containing networks.