José Salta

Studies of the oxovanadium(IV)—oxalate system: syntheses and crystal structures of binuclear (Ph4P)2[(VO)2(H2O)2(C2O4)3]·4H2O and of the one-dimensional chain material, (Ph4P)[VOCl(C2O4)]

Abstract The hydrothermal reactions of (Ph4P)[VO2Cl2] and H2C2O4 at 150 and 125°C yield (Ph4P)2[V2O2(H2O)2(C2O4)3]·4H2O (1) and (Ph4P)[VOCl(C2O4)] (2), respectively. The structure of the molecular anion of 1 consists of a binuclear unit of oxovanadium(IV) octahedra bridged by a bisbidentate oxalate group. The VO6 coordination geometry at each vanadium site is defined by a terminal oxo group, an aquo ligand, and four oxygen donors — two from the bisbidentate bridging oxalate and two from the terminal bidentate oxalate. The structure of 2 consists of discrete Ph4P+ cations occupying regions between [VOCl(C2O4)]−∞ spiral chains. The structure of the one-dimensional anionic chain exhibits V(IV) octahedra bridged by bisbidentate oxalate groups. Crystal data: 1·4H2O, monoclinic P2 1 /n, a = 12.694(3), b = 12.531(3), c = 17.17(3) A , β = 106.32(2)°, V = 2621.3(13) A 3 , Z = 2, D calc = 1.501 g cm −3 , structure solution and refinement converged at a conventional residual of 0.0518; 2, tetragonal P4 3 , a = 12.145(2), c = 15.991(3) A , V = 2358.7(12) A 3 , Z = 4, R = 0.0452 .

Oxovanadium alkoxide complexes. Syntheses and crystal structures of (Ph4P)2[(VO)2Cl4(OR)2] (R = −CH3, −CH2CH2Cl) and [(VO)2Cl2MeC(CH2OH) (CH2O)22]

Abstract The reactions of (Ph4P) [VO2Cl2] in various alcohols yield complexes of the type (Ph4P)2[(VO)2Cl4(OR)2] (R=−CH3(1), −CH2CH2Cl (2)). Similarly, the reaction of (BzPh3P) [VO2Cl2] with tris(hydroxymethyl)ethane yields [(VO)2Cl2MeC(CH2OH)(CH2O)22]∗d2BxPh3PCl∗d2CH3OH (3∗d2BzPh3PCl∗d2CH3OH). The molecular anions of complexes 1 and 2 consist of binuclear units of edge-sharing V(IV) square pyramids. The alkoxy groups bridge the two V(V) sites and the ∗ V=O ∗ groups adopt the anti-orientation with respect to the V2O2 rhombus of the bridging unit. In contrast, the neutral [(VO)2Cl2MeC(CH2OH)(CH2O)22] consists of the edge-sharing V(V) octahedra. The tridentate ligands each provide one alkoxy oxygen adopting a bridging mode between V(V) sites, an alkoxy oxygen as a terminal ligand to one V(V) site and an alcohol oxygen donor as a terminal ligand to the other V(V) site. The terminal oxo-groups occupy positions approximately coplanar to the V2O2 rhombus of the bridging unit. Crystal data: (Ph4P)2[(VO)2Cl4(OCH3)2]∗d2CH3OH (1∗d2CH3OH), monoclinic P2 1 /n, a = 12.068(2), b = 16.388(3), c = 12.893(3) A , β = 100.72(2)°, Z =2 . (Ph4P)2[(VO)2Cl4-(OCH2CH2Cl)2] (2), triclinic P l , a = 11.227(2), b = 12.496(2), c = 10.609(2) A , α = 109.78(2), β = 114.68(3), γ = 85.46(3)°, Z = 1 . [(VO)2Cl2MeC(CH2OH)(CH2O)22]∗d2BzPh3PCl∗d2CH3OH (3∗d2BzPh3PCl∗d2CH3OH), triclinic P 1 , a = 10.361(2), b = 15.762(3), c = 10.125(2) A , α = 105.72(3), β = 90.02(3), γ = 79.86(3)°, Z = 1 .

Studies of the oxovanadium-organophosphonate system: Formation of pyrodiphosphonate and pyrophosphophosphonate units through metal-mediated ligand condensations. The crystal and molecular structures of (Ph4P)2[VO{RP(O)2OP(O)2R}2] (R=Me, Ph) and (Ph4P)2(n-Bu4N)[(VO)6V{t-BuP(O)2OPO3}6]

Under solvothermal conditions and in the presence of oxovanadium species. organophosphonates undergo self-condensation reactions or condensation with phosphate to yield pyrodiphosphonate {RP(O)2OP(O)2R}2, or organophos-phonatophosphate units {RP(O)2OPO3}3-. In this fashion, the reactions of (Ph4P)[VO2Cl2] withRPO3H2 (R=CH3,Ph) and Et3N in CH3CN at 110°C yielded (Ph4P)2 [VO{RP(O)2P(O)2R}2](R = CH3(1), Ph (2)). However, the reaction of {Ph4P}[VO2Cl2],t-BuPO3H2 and (n-Bu4N)H2PO4 in acetonitrile at 125°C produced an unusual mixed valence V(IV)/V(III) cluster (Ph4P)2 (n-Bu4N)[(VO)6V{Me3CP(O)2OPO3}6] ⊎3CH3CN (3). Compounds1 and2 exhibit mononuclear molecular anions with the V(IV) center in the common square pyramidal coordination mode. The organodiphosphonate ligands adopt a bidentate coordination mode. The molecular anion of3 consists of a shell constructed of six V(IV) square pyramids linked by pentadentate {Me3CP(O)2OPO3}3- groups. Each organophosphonatophosphate ligand bridges four {VO5}square pyramids of the shell and directs the fifth oxygen donor toward the interior of the cluster, so as to bond to an octahedral V(III) located at the center of the cluster cavity. Crystal data:1, C26H26O5.5P3V0.5: triciinic Pl,a=10.836(2)A,b=ll.418(2)A,c=11.486(2)A,α=82.58(2)°,ß=75.29(2)°,γ=75.61(2)°,V=1328.1(7)A3,Z=2, Dcalc=l.362gcm-3;2, C36H32O6.5P3V0.5: monoclinic P21/c,a=12.823(3)A,b=14.318(3)A,c=18.581(4)A,ß=94.76(3)°,V=3999.7(13)A3,Z=4, Dcalc=l.342gcm-33, C94H139N4O42P14V7, triclinic Pl,a=13.589(3)A,b=17.835(4)A,c=38.915(8)A,α=81.64(2)°,ß=81.58(2)°,γ=82.87(2)°,V=9180(3)A3,Z=3, Dcalc=l.512gcm-3.

Solvatothermal synthesis and crystal structure of (Ph4P) [(VO2)4 (CH3CO2)4Cl]

Abstract The solvatothermal reaction of (Ph 4 P)[VO 2 Cl 2 ] with acetic acid in methylene chloride at 100°C for 48 h yields bright red crystals of (Ph 4 P) [(VO 2 ) 4 (CH 3 CO 2 ) 4 Cl] ( 1 )in 20% yield. The structure of the anion of 1 consists of a tetrakis (μ-acetato-μ-oxo-oxovanadium)crown with a chloride guest anion occupying the hollow formed by the edge-sharing of the four {VO 5 } square pyramids. Crystal data: C 32 H 32 O 16 PClV 4 , tetragonal I4 1 /a,a = 15.969(2), c = 29.020(5) A , V = 7400(1) A 3 , Z = 8 .

Studies of the oxovanadium-organophosphonate system. The synthesis and crystal structure of (Et3NH)2 [(VO)2(acac)2(O3PCH2PO3)]

Abstract The reaction of [VO(acac)2], methylenediphosphonic acid and triethylamine in acetonitrile at 110°C for 60 h yields (Et3NH)2-[(VO)2(acac)2(O3PCH2PO3)] (1). The structure of 1 consists of two {VO(acac)} moieties linked by a methylenediphosphonate group in the bisbidentate bridging mode. The {(VO)2(O3PCH2PO3)} core of 1 provides a fundamental structural motif for one-dimensional oxovanadium methylenediphosphonate phases. Crystal data: C23H48N2O12P2V2: orthorhombic P22121, a = 9.767(2), b = 17.189(3), c = 20.736(4) A , V = 3481.3(12) A 3 , Z = 4, Dcalc = 1.35 g cm−3; structure solution and refinement based on 2022 reflections converged at R = 0.068.

Studies of the oxovanadium-organophosphonate system: Hydrothermal synthesis and crystal structure of the mixed valence cluster [V5O9(PhPO3)3(PhPO3H)2]2− and a comparison to the structure of the fully oxidized parent cluster [V5O7(OCH3)2(PhPO3)5]1−

AbstractThe room temperature reaction of (Bu4N)3V5O14 with PhPO3H2 in methanol yields the pentanuclear V(V) cluster (Bu4N)[V5O7(OCH3)2(PhPO3)5]·CH3OH (1·CH3OH). In contrast, the hydrothermal reaction of (Ph4P) [VO2Cl2], PhPO3H2 and (NH4)H2PO4 at 125°C for 96 hr yields the mixed valence V(IV)/V(V) species (Ph4P)2[V5O9(PhPO3)3(PhPO3H)2] (3). While the anions of both 1 and 3 exhibit a pentanuclear core, the structural consequences of 1-electron reduction of the fully oxidized cluster of 1 to produce 3 are quite dramatic, including reduction in coordination numbers at two vanadium sites and protonation of two phosphonate oxygen sites with concomitant structural reorganization. Crystal data: 1, monoclinic P21/n,a=12.167(2) Å,b=23.348(5) Å,c=22.508(5) Å,β=98.49(2)°,V=6323.9(19) Å3,Z=4,Dcalc=1.558 g cm−3; 3, triclinic,

Investigations of the V/O/RAsO32– system: solvothermal synthesis and crystal and molecular structure of [(V2O3)(Ph6As6O14)]

P\bar 1

SYNTHESIS AND CHARACTERIZATION OF BINUCLEAR OXO-VANADIUM COMPLEXES OF CARBON OXANION LIGANDS. CRYSTAL STRUCTURE OF THE BINUCLEAR VANADIUM(IV) COMPLEX (NH4)V2O2(OH)C4O4)2(H2O3.H2O, OF THE MIXED-VALENCE VANADIUM(V)/VANADIUM(VI) -SQUARATE SPECIES (N-C4H9)4NV2O3(C4O4)2(H2O)3.3H2O AND (C4H9)4N4V4O6(C4O4)5

,a=13.478(3) Å,b=14.399(3) Å,c=23.638(5) Å,α=72.53(2)°,β=85.58(2)°,γ=69.88(4)°,V=4107.0(16) Å3,Z=2, Dcalc=1.479 g cm−3.