Paul DeBurgomaster

Hydrothermal chemistry of vanadium oxides with aromatic di- and tri-phosphonates in the presence of secondary metal copper(II) cationic complex subunits

The hydrothermal chemistry of the copper-organonitrogen ligand/vanadium oxide/aromatic phosphonate system has been studied. Not only was HF required to induce crystallization, but product composition was highly dependent on the HF/V ratio of the reactions. At relatively low concentrations of HF/V of 6:1, materials of the Cu(II)-ligand/VxOy/organophosphonate type were observed, namely, [{Cu(phen)}2V2O5(O3PC6H4PO3)] (1), [Cu(phen)VO2(HO3PC6H4PO3)] (2), [{Cu(terpy)}2V2O5(O3PC6H4PO3)] (3), [{Cu(phen)(H2O)}VO2(HO3PC6H4PO3)] (6), [{Cu(phen)}VO2(HO3PC6H4PO3)] (7a and 7b), [Cu(C5H4NCO2)2V2O4(HO3PC6H4POH3)] (8), [Cu(bpy)VO2 {(HO3P)3C6H3}]·1.5H2O (12·1.5H2O), [{Cu(bpy)}2V3O7{(O3P)2C6H3PO3H}] (13) and [Cu(phen)V3O6(H2O){(O3P)2C6H3(PO3H)}] (14). When the HF concentration was raised, materials incorporating fluoride anion were observed; that is, compounds of the Cu(II)-ligand/VxOyFz/organophosphonate type: [{Cu(bpa)}2VO2F(H2O)(O3PC6H4PO3)]·H2O (4), [{Cu(bpa)}2V2O4F2(O3PC6H4PO3)] (5), [{Cu(bpy)}2V2O4F2(O3PC6H4PO3)] (9), [{Cu(terpy)}2V3O6F(HO3PC6H4PO3)2] (10), [{Cu(bpa)}2V2O4F2(O3PC6H4PO3)] (11). At HF/V concentrations of 25:1 or greater, vanadium free products, Cu(II) ligand/organophosphonate, were obtained: [Cu(C5H4NCO2)2(H2O3PC6H4PO3H2)]·H2O (15·H2O), [Cu(C5H4NCO2)2(H2O3PC6H4PO3H2)] (16), [Cu(bpy)(H2O){(HO3P)2C6H3(PO3H2)}] (17), [Cu(bpy){(HO3P)2C6H3(PO3H2)}]·H2O (18·H2O), [Cu(phen){(H2O3P)C6H3(PO3H)2}]·2H2O (19·2H2O) and [Cu(bpa){H2O3PC6H3(PO3H)2}]·H2O (20·H2O). The structural chemistry is unusually diverse with the Cu(II) ligand/VxOy/organophosphonate series exhibiting one-, two- and three-dimensional structures with a variety of copper-vanadate and vanadophosphonate substructures. The structural chemistry is discussed in relation to other examples of materials of the Cu(II) ligand/VxOy/organophosphonate and Cu(II) ligand/VxOyFz/organophosphonate families.

A binuclear molybdenum oxyfluoride: μ-oxido-bis­[(2,2′-bipyrid­yl)fluoridodioxidomolybdenum(VI)]

The title compound, [Mo2F2O5(C10H8N2)2], is a centrosymmetric binuclear molybdenum(VI) species with the metal atoms in a distorted octahedral environment. The coordination geometries of the symmetry-equivalent molybdenum sites are defined by the cis-terminal oxide groups and the N-atom donors of the bipyridyl ligand in the equatorial plane with axial F and bridging O atoms. The bridging O atom occupies a center of symmetry. The molecules stack in the a-axis direction, and the crystal packing is stabilized by weak intra- and intermolecular C—H⋯O and C—H⋯F hydrogen bonds.

A binuclear vanadium oxyfluoride: di-μ-oxido-bis-[fluoridooxido(1,10-phenanthro-line)vanadium(V)].

The title compound, [V2F2O4(C12H8N2)2], is a centrosymmetric binuclear vanadium(V) species with the metal ions in a distorted octahedral environment. The symmetry-equivalent VV atoms exhibit coordination geometries defined by cis-terminal fluoride and oxide groups, unsymmetrically bridging oxide groups and the N-atom donors of the phenanthroline ligands. The crystal packing is stabilized by weak intermolecular C—H⋯O and C—H⋯F hydrogen bonds.

A one-dimensional copper(II) phenyl-ene-diphospho-nate: catena-poly[[(1,10-phenanthroline-κN,N')copper(II)]-μ(3)-[m-phenyl-enediphospho-nato-κO:O':O'']].

The title compound, [Cu(1,3-HO3PC6H4PO3H)(C12H8N2)]n, is a coordination polymer of the metal–diphosphonate family. The chain structure is constructed from ‘4+1’ square-pyramidally coordinated copper(II) atoms bonded to chelating phenanthroline (phen) ligands and linked through 1,3-phenyldihydrogendiphosphonate ligands. The basal plane of the Cu(II) site is defined by the phen nitrogen donors and phosphonate oxygen atoms from two diphosphonate ligands, while the apical position is occupied by an oxygen donor from a third diphosphonate ligand. The chains propagate along the a-axis direction. Inversion-related phen groups engage in π-π stacking with a mean distance of 3.376 (2) Å between the ring planes. O—H⋯O hydrogen-bonding interactions between the protonated {P—OH} groups of one chain and the {P=O} groups of adjacent chains stabilize the crystal packing.

A binuclear vanadium oxyfluoride: di-μ-oxido-bis­[(2,2′-bipyrid­yl)fluorido­oxidovanadium(V)]

The title compound, [V2F2O4(C10H8N)2], is a centrosymmetric binuclear vanadium(V) species with the metal ions in a distorted octahedral environment. The coordination geometries of the symmetry-equivalent VV atoms are defined by cis-terminal fluoride and oxide groups, unsymmetrically bridging oxide groups and the N-atom donors of the bipyridyl ligand. The crystal packing is stabilized by weak intermolecular C—H⋯O and C—H⋯F hydrogen bonds.

[μ-2,3,5,6-Tetra­kis(2-pyrid­yl)pyrazine-κ6 N 6,N 1,N 2:N 3,N 4,N 5]bis­[diaqua(dihydrogen m-phenylene­diphospho­nato-κO)nickel(II)] dihydrate

The title compound [Ni2(C6H6O6P2)2(C24H16N6)(H2O)4]·2H2O or [Ni2(tpyprz)(1,3-HO3PC6H4PO3H)2(H2O)4]·2H2O [tpyprz = tetrakis(2-pyridyl)pyrazine, C24H16N6] is a binuclear complex with a crystallographic inversion center located at the center of the pyrazine ring. The equivalent nickel(II) sites exhibit a distorted {NiO3N3} octahedral coordination, with the three nitrogen donors of each terminus of the tpyprz ligand in a meridional orientation. An aqua ligand occupies the position trans to the pyrazine nitrogen donor, while the second aqua ligand is trans to the oxygen donor of the dihydrogen-1,3-phenyldiphosphonate ligand. The Ni—O and Ni—N bond lengths fall in the range 2.011 (3) to 2.089 (3) Å. The protonation sites on the organophosphonate ligand are evident in the significantly longer P—O bonds compared to the unprotonated sites. In the crystal structure, the complex molecules and the solvent water molecules are linked into a three-dimensional hydrogen-bonded framework through O—H⋯O interactions between the aqua ligands, the protonated organophosphonate oxygen atoms and the water molecules of crystallization. Intramolecular π-stacking between the phenyl group of the phosphonate ligand and a pyridyl group of the tpyprz ligand, at a distance of 3.244 (5) Å between ring centroids, is also observed.

[μ-2,3,5,6-Tetrakis(2-pyridyl)pyrazine κ6N 6,N1,N2: N3,N4,N 5]bis[diaqua(dihydrogen m-phenylenediphosphonato κo) nickel(II)] dihydrate

The title compound [Ni2(C6H6O6P2)2(C24H16N6)(H2O)4]·2H2O or [Ni2(tpyprz)(1,3-HO3PC6H4PO3H)2(H2O)4]·2H2O [tpyprz = tetrakis(2-pyridyl)pyrazine, C24H16N6] is a binuclear complex with a crystallographic inversion center located at the center of the pyrazine ring. The equivalent nickel(II) sites exhibit a distorted {NiO3N3} octahedral coordination, with the three nitrogen donors of each terminus of the tpyprz ligand in a meridional orientation. An aqua ligand occupies the position trans to the pyrazine nitrogen donor, while the second aqua ligand is trans to the oxygen donor of the dihydrogen-1,3-phenyldiphosphonate ligand. The Ni—O and Ni—N bond lengths fall in the range 2.011 (3) to 2.089 (3) Å. The protonation sites on the organophosphonate ligand are evident in the significantly longer P—O bonds compared to the unprotonated sites. In the crystal structure, the complex molecules and the solvent water molecules are linked into a three-dimensional hydrogen-bonded framework through O—H⋯O interactions between the aqua ligands, the protonated organophosphonate oxygen atoms and the water molecules of crystallization. Intramolecular π-stacking between the phenyl group of the phosphonate ligand and a pyridyl group of the tpyprz ligand, at a distance of 3.244 (5) Å between ring centroids, is also observed.

[μ-2,3,5,6-Tetra­kis(2-pyrid­yl)pyrazine-κ6N6,N1,N2:N3,N4,N5]bis­[diaqua(dihydrogen m-phenylene­diphospho­nato-κO)nickel(II)] dihydrate

The title compound [Ni2(C6H6O6P2)2(C24H16N6)(H2O)4]·2H2O or [Ni2(tpyprz)(1,3-HO3PC6H4PO3H)2(H2O)4]·2H2O [tpyprz = tetrakis(2-pyridyl)pyrazine, C24H16N6] is a binuclear complex with a crystallographic inversion center located at the center of the pyrazine ring. The equivalent nickel(II) sites exhibit a distorted {NiO3N3} octahedral coordination, with the three nitrogen donors of each terminus of the tpyprz ligand in a meridional orientation. An aqua ligand occupies the position trans to the pyrazine nitrogen donor, while the second aqua ligand is trans to the oxygen donor of the dihydrogen-1,3-phenyldiphosphonate ligand. The Ni—O and Ni—N bond lengths fall in the range 2.011 (3) to 2.089 (3) Å. The protonation sites on the organophosphonate ligand are evident in the significantly longer P—O bonds compared to the unprotonated sites. In the crystal structure, the complex molecules and the solvent water molecules are linked into a three-dimensional hydrogen-bonded framework through O—H⋯O interactions between the aqua ligands, the protonated organophosphonate oxygen atoms and the water molecules of crystallization. Intramolecular π-stacking between the phenyl group of the phosphonate ligand and a pyridyl group of the tpyprz ligand, at a distance of 3.244 (5) Å between ring centroids, is also observed.

Catena-Poly[[bis-(μ-5-bromo-pyridine-3-carboxyl-ato-κ2 O: O′)dicopper(II)]-bis-(μ-5-bromo-pyridine-3-carboxyl-ato) -κ3 O,O′:N;κ3 N:O,O′]

The title compound [Cu2(C6H3BrNO2)4]n, forms sheets in the bc plane. The structure features the dinuclear paddle-wheel cage motif common to copper(II) carboxylates. The polymeric structure is achieved through bridging between binuclear units by the pyridyl donors of two of the four carboxylates of the cage. Each cage engages in axial bonding at each copper atom to a pyridyl nitrogen donor and extends two 5-bromopyridine-3-carboxylate groups to bridge to adjacent binuclear sites in the bc plane. Each cage is linked to four adjacent cages in the plane. The intradimer Cu⋯Cu distance is 2.6465 (5) Å. The remaining 5-bromopyridine-3-carboxylate groups project into the interlamellar domain and interdigitate in pairs from each neighboring layer.

(Di-2-pyridyl-amine)-(methanol)sulfato-copper(II).

The title complex, [Cu(SO4)(C10H9N3)(CH3OH)], is a mononuclear species with the CuII ion in a Jahn–Teller-distorted ‘4 + 1’ square-pyramidal geometry. The basal plane is defined by the pyridyl N-atom donors of the bipyridylamine (bpa) ligand and two O-atom donors of the sulfate ligand. The coordination geometry is completed by the axial coordination of a methanol O-atom donor. The axial bond length displays the usual elongation: Cu—O(axial) = 2.168 (2), Cu—O(basal) = 2.016 (2) (average) and Cu—N(basal) = 1.951 (3) Å (average). In the crystal structure, the complex molecules are linked through N—H⋯O and O—H⋯O hydrogen bonds into chains along [100].