Two Inorganic-Organic Hybrid Crystals Based on [SMo12O40]2- Polyoxometallates and Supramolecular Cation: Syntheses and Crystal Structures

Two inorganic-organic hybrids, [(4-I-Anis)([18]crown-6)](2)[SMo12O40]center dot CH3CN (1) and [(3-F-4-Cl-Anis)(2) (DB [30]crown-10)] [SMo12O40]center dot 2CH(3)CN (2) (4-I-Anis = 4-iodoanilinium; 3-F-4-Cl-Anis =3-fluoro-4-chloroanilinium; DB[30]crown-10=dibenzo[30]crown-10) have been synthesized and characterized by infrared spectrum (IR), elemental analysis (EA), powder XRD, thermogravimetric (TG), solid state diffuse reflectance spectra (DRS) and X-ray diffraction. Crystals 1 and 2 are constructed through noncovalent bonding interaction, and the polyoxometalates and supramolecular cation arrange alternately. Supramolecular cation forms through the N-H center dot center dot center dot O hydrogen bonding interaction between the nitrogen atom of anilinium and oxygen atoms of crown ether derivatives. In crystal 1, each polyoxoanion is surrounded by six monovalent supramolecular cations (4-I-Anis) ([18]crown-6) and forms hexagonal arrangement in be plane. In crystal 2, each polyoxoanion is surrounded by four large supramolecular cations (3-F-4-Cl-Anis)2(DB[30]crown-10) and forms tetragonal arrangement in be plane. TG measurement indicated that hydrogen bonding interaction plays an important role in maintaining the structural stability of crystals 1 and 2. DRS indicated that there exists charge-transfer interaction between [SMo12O40](2-) polyoxoanions and crown ether based supramolecular cations in crystals 1 and 2. CCDC: 1540103, 1; 1899810, 2.