Synthesis and structural characterization of a series of carboxylic acid modified cerium(III) alkoxides

A series of cerium alkoxides were synthesized from the reaction of Ce(N[Si(CH(3))(3)](2))(3) and the appropriate alcohol: neopentyl alcohol [H-OCH(2)C(CH(3))(3) = H-ONep], tert-butyl alcohol [H-OC(CH(3))(3) = H-OtBu], o-(tert-butyl)phenol {H-OC(6)H(4)[C(CH(3))(3)]-2 H-oBPI, 2,6-dimethylphenol [H-OC(6)H(3)(CH(3))(2)-2,6 H-DMP], 2,6-diisopropylphenol [H-OC(6)H(3)[CH(CH(3))(2)]2-2,6 = H-DIP), 2,6-di-tert-butylphenol {H-OC(6)H(3)[C(CH(3))(3))(2)-2,6 = H-DBP), or 2,6-diphenylphenol [H-OC(6)H(3)(C(6)H(5))(2)-2,6 = H-DPP] using toluene (tol), tetrahydrofuran (THF) or pyridine (py). The precursors were characterized as [Ce(mu-ONep)(2)(ONep)](4) (1), Ce(4)(mu(3)-OtBU)(3)(mu-OtBU)(4)(OtBU)(5) (2), Ce(3)(mu(3)-OtBU)(3)(mu-OtBU)(3)(OtBu)(3)(H-OtBU)(2) (2a), Ce(oBP)(3)(THF)(3) (3), [Ce(mu-DMP)(DMP)(2)(solv)(2)](2) [solv = THF (4) and py (4a)], Ce(DIP)(3)(THF)(3) (5), Ce(DPP)(3)(THF)(2) (6). Once isolated, several of these species were further reacted with a series of sterically varied carboxylic acid modifiers including isobutyric acid [H-O(2)CCH(CH(3))(2) = H-OPc] and trimethylacetic acid [H-O(2)CC(CH(3))(3) = H-OBc]. The products were isolated as [Ce(OR)(mu-ORc)(mu(c)-ORc)(py)](2) [OR = oBP, OBc: 7; DMP, OPc: 8; DMP, OBc: 9; DIP, OI)c: 10]. These compounds were identified by single-crystal X-ray diffraction and powder XRD analyses. Several novel structure types are added to the cerium alkoxide family of compounds.