122423-58-9Relevant articles and documents
Synthetic and structural studies of a series of soluble cerium (IV) alkoxide and alkoxide nitrate complexes
Evans, William J.,Deming, Timothy J.,Olofson, Jeffrey M.,Ziller, Joseph W.
, p. 4027 - 4034 (2008/10/08)
The reactions of (NH4)2Ce(NO3)6 (CAN) with 2-8 equiv of NaOCMe3 in THF and in tert-butyl alcohol have been studied. A series of ceric alkoxide complexes of general formula Ce(OCMe3)a,(NO3)b(solvent) cNad (a = 1-6; b = 0-3; c = 2, 4; d = 0, 2; a + b = 4 + d) have been identified as well as Ce2(OCMe3)9Na and Ce3(OCMe3)10O. Interconversion of these complexes by treatment with NaOCMe3 or NH4NO3 has also been studied. CAN reacts with 3 equiv of NaOCMe3 in THF to form Ce(OCMe3)(NO3)3(THF)2 (1). In tert-butyl alcohol this reaction forms the HOCMe3 solvate Ce(OCMe3)(NO3)3(HOCMe3)2 (1′). 1 reacts with 1 equiv of NaOCMe3 and CAN reacts with 4 equiv of NaOCMe3 to form Ce(OCMe3)2(NO3)2(THF)2 (2). In tert-butyl alcohol solvent, 1′ reacts with NaOCMe3 to form Ce(OCMe3)2(NO3)2(HOCMe 3)2 (2′). 2′ crystallizes from a concentrated toluene solution at -34°C in space group P1 (No. 2; Ci1) with a = 10.7548 (56) A?, b = 11.0853 (49) A?, c = 12.4403 (56) A?, α = 72.760 (34)°, β = 88.190 (39)°, γ = 69.050 (35)°, V = 1318.0 (11) A?3, and Z = 2 for Dcalcd = 1.41 g cm-3. Least-squares refinement of the model based on 4935 observed reflections converged to RF = 7.7%. If each NO3 ligand is taken to occupy just one coordination site, the structure of 2′ is that of a distorted octahedron in which identical ligands are trans to each other. Ce(OCMe3)3(NO3)(THF)2 (3) can be prepared from 2 or 2′ and NaOCMe3 or from CAN and 5 equiv of NaOCMe3. Ce(OCMe3)4(THF)2 (4) is prepared from 3 and NaOCMe3 or from CAN and 6 equiv of NaOCMe3. The reaction of 4 with 2 equiv of NaOCMe3 or reaction of CAN with 8 equiv of NaOCMe3 forms Ce(OCMe3)6Na2(THF)4 (5). 5 crystallizes from dimethoxyethane (DME) at -34°C as Ce(OCMe3)6Na2(DME)2 (5′) in space group Pna21 with a = 20.5337 (36) A?, b = 10.9557 (23) A?, c = 19.4128 (38) A?, V = 4367.1 (15) A?3, and Z = 4 for Dcalcd = 1.22 g cm-3. Least-squares refinement of the model based on 9092 observed reflections converged to RF = 4.9%. 5′ contains a distorted-octahedral arrangement of OCMe3 groups around cerium. Each sodium ion is coordinated by one DME ligand and a facial set of three OCMe3 groups of the Ce(OCMe3)62- octahedron. The reaction of 4 with 1/2 equiv of NaOCMe3 forms Ce2(OCMe3)9Na (6). Both 4 and 6 in toluene slowly form Ce3(OCMe3)10O (7). Complex 5 reacts with 5 equiv of NH4NO3 to form 1 in quantitative yield.
