Cd(NH2SO3)2·xH2O (x = 0, 2): new sulfamates with a unique coordination environment and reversible phase transitions

• Published in: Inorganic chemistry frontiers 2023-02, Vol.10 (5), p.1411-1420
• Main Authors: Wang, Xuefei, Lee, Jihyun, Yang, Li, Kuk, Yunseung, Kang, Min Ok
• Format: Article
• Language: English
• Subjects: Dehydration; Inorganic chemistry; Phase transitions; Tetrahedra
• ISSN: 2052-1545; 2052-1553
• DOI: 10.1039/d2qi02479a

Two new cadmium sulfamates, namely, centrosymmetric Cd(NH2SO3)2·2H2O and noncentrosymmetric Cd(NH2SO3)2 have been successfully synthesized. Crystals of Cd(NH2SO3)2·2H2O grown using an aqua-solution method reveal an infinite chain structure consisting of trans-[CdO2(H2O)2(NH2)2] octahedra and [NH2SO3] units. Crystals of Cd(NH2SO3)2 obtained during the process of dehydration of Cd(NH2SO3)2·2H2O exhibit a 3D framework composed of cis-[CdO4(NH2)2] octahedra and [NH2SO3] tetrahedra. Temperature- and humidity-induced reversible phase transitions of the title compounds are observed, which is confirmed by TGA and PXRD. Cd(NH2SO3)2 exhibits a phase-matchable SHG response of ca. 0.15 × KDP. Interestingly, nitrogen-containing [CdO4N2] octahedra are found in the metal sulfamates for the first time. The unique arrangement is discussed with the hard-and-soft acids and bases theory and further compared with other existing [MO6] (M = Na, Mg) octahedra in sulfamates. In addition, the discovery would provide a new perspective to design new materials by adjusting the structural arrangement for polar anionic groups.