Covalent Co–O–V and Sb–N Bonds Enable Polyoxovanadate Charge Control

Abstract

The formation of [{CoII(teta)2}{CoII2(tren)(teta)2}VIV15SbIII6O42(H2O)]·ca.9H2O [teta = triethylenetetraamine; tren = tris(2-aminoethyl)amine] illustrates a strategy toward reducing the molecular charge of polyoxovanadates, a key challenge in their use as components in single-molecule electronics. Here, a V–O–Co bond to a binuclear Co2+-centered complex and a Sb–N bond to the terminal N atom of a teta ligand of a mononuclear Co2+ complex allow for full charge compensation of the archetypal molecular magnet [V15Sb6O42(H2O)]6–. Density functional theory based electron localization function analysis demonstrates that the Sb–N bond has an electron density similar to that of a Sb–O bond. Magnetic exchange coupling between the VIV and CoII spin centers mediated via the Sb–N bridge is comparably weakly antiferromagnetic.

New Water‐Soluble Cluster Compound {Zn(en)3}3[V15Sb6O42(H2O)]⋅ (Ethylenediamine)3⋅10 H2O as a Synthon for the Generation of Two New Antimonato Polyoxovanadates

“…The arrangemento ft he VO 5 polyhedra generates two hexagons of edge-sharing VO 5 pyramids (Figure 3l eft, pink and green pyramids). [20] The Zn 2 + -centered complexes and the cluster anions are arrangeda lternatingly along[ 010] and [001] (Figure 4), and each cluster is surrounded by eight complexes ( Figure S13). [5-9, 12-19, 21, 22, 25, 26] Determination of the oxidation states by bond valence sum (BVS [27] )c alculations indicated the presence of V IV centers in all three compounds ( (Figures S10-S12).…”

Unprecedented Connection Mode of [V16Sb4O42(H2O)]8– Cluster Anions by Mn2+ Centered Complexes: Solvothermal Synthesis and Properties of {[Mn(teta)]4V16Sb4O42(H2O}n·[(H2O)12]n

“…All geometric parameters are in the range reported for POVs. [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][25][26][27][28][29][30][31][32][33][34][35] (Tables S2 and S3). There are only two structures reported in the CCDC, in which a Mn 2+ cation is coordinated by one teta ligand and two O atoms.…”

“…[8] While in this compound the {V 16 Sb 4 } core is expanded by a central V IV atom, the application of other transition metal cations in the reaction slurries generated a variety of Sb-POVs with variable dimensionalities. [9][10][11][12][13][14][15][16][17] The chemistry and structural diversity could be expanded by formation of inorganic-organic hybrid structures like observed in [V 14 [18] or in [{Co II (teta) 2 [19] While all these compounds were synthesized under solvothermal conditions applying Sb and V compounds as starting materials, further Sb-POVs could be prepared recently applying a water soluble Sb-POV. [20][21][22] In literature 34 Sb-POVs have been reported, of which 11 belong to the {V 14 16 } cluster is interconnected by a transition metal complex to form a chain, [9] while in all other {V 16 } anion based compounds cations and anions are isolated.…”

Soluble Hetero‐Polyoxovanadates and Their Solution Chemistry Analyzed by Electrospray Ionization Mass Spectrometry

“…Compound 12 features a close interaction between one nitrogen atom of all three ethylenediamine molecules and three of the Sb atoms with Sb−N distances significantly shorter than the sum of their van der Waals radii. As was shown recently, such short Sb−N distances must be treated as covalent bonds with a strength comparable to a Sb−O bond . In the structure of 13 , {V 15 Sb 6 O 42 } clusters are connected to their next neighbors by [Zn(en) 2 ] 2+ complexes forming a chain along [101].…”

“…[19] Also, other compound properties and their chemical behavior are characterized by the lone electron pairs of As III and Sb III .T hey lead to as teric hindrance around the heteroatom and can act as potential bonding partners. [19] The knownS b-POVs can be described with the archetypal {V 18 O 42 }b yf ormal substitution of two, three or four VO 5 pyramids by two, three or four handle-like Sb 2 O 5 moieties resulting in the most common {V 16 Sb 4 O 42 }-, [25][26][27][28][29] {V 15 Sb 6 O 42 }- [25,27,[30][31][32][33][34][35] and {V 14 Sb 8 O 42 }-types [28-30, 32, 36-39] (Figure 4).…”