Bis(µ-methano-lato-κO:O)bis-{[4-bromo-N'-(1-methyl-3-oxidobut-2-en-1-yl-idene-κO)benzohydrazidato-κN',O]oxido-vanadium(V)}.

The dinuclear compound, [V(2)(C(12)H(11)BrN(2)O(2))(2)(CH(3)O)(2)O(2)], lies on a center of inversion. The doubly-deprotonated Schiff base O,N,O'-chelates to the V(V) atom; two metal atoms are bridged by the methoxide units. The coordination geometry is a distorted octa-hedron. Weak inter-molecular C-H⋯N hydrogen bonding is present in the crystal structure. The bromo-phenyl unit is disordered over two positions, with the major component being in a 0.909 (6) proportion.

Poly[µ-aqua-aqua-{µ-6-eth-oxy-2-[(2-isonicotinoylhydrazinyl-idene)meth-yl]phenolato-κO,N,O'}dioxidosodium-vanadate(V)].

The V(V) atom in the polymeric title compound, [NaV(C(15)H(13)N(3)O(3))O(2)(H(2)O)(2)](n), is O,N,O'-chelated by the Schiff base dianion and is five-coordinated in a trigonal-bipramidal coordination geometry. The oxide O atoms occupy the equatorial sites and one oxide O atom is connected to the Na(I) atom. The ligand simultaneously O,O'-chelates to the water-coordinated Na(I) atom; its coordination number is seven owing to an Na⋯N(pyrid-yl) bond. The two independent formula units, which are disposed about a false center of inversion, are connected into a layer. Adjacent layers are consolidated into a three-dimensional network by O-H⋯O and O-H⋯N hydrogen bonds.

(4-Methyl-benzohydrazidato-κN',O)[2-(4-methyl-benzoyl-hydrazinyl-idene-κN,O)-3-phenyl-propionato(2-)]oxido-vanadium(V) methanol monosolvate.

The V(V) atom in the title compound, [V(C(8)H(9)N(2)O)(C(17)H(14)N(2)O(3))O]·CH(3)OH, is N,O-chelated by the benzoyl-hydrazidate anion and O,N,O'-chelated by the (benzoyl-hydrazono)propionate dianion. The octa-hedral trans-N(2)O(4) coordination geometry is completed by the vanadyl O atom. Two mononuclear complexes and two solvent mol-ecules are linked by O-H⋯O and O-H⋯N hydrogen bonds, generating a centrosymmetric aggregate.

(Acetyl-acetone isonicotinoylhydrazonato-κO,N',O')dioxidovanadate(V) monohydrate.

The hydrazone anion in the title compound, [V(C(11)H(12)N(3)O(2))O(2)]·H(2)O, is zwitterionic as its pyridyl N atom is protonated; the O, N and O' atoms span the axial-equatorial-axial positions of the trigonal-bipyramidal coord-in-ation polyhedron of the metal atom. All non-H atoms lie on a crystallographic mirror plane apart from the oxide ligands, which are related by mirror symmetry. The pyridinium N atom acts as a hydrogen-bond donor to the solvent water mol-ecule, which is in turn a hydrogen-bond donor to the both oxide ligands. These hydrogen-bonding inter-actions give rise to a three-dimensional network motif.

(Acetyl-acetone 3-hy-droxy-2-naphtho-yl-hydrazonato-κO,N',O')(methoxo-κO)oxidovanadate(V).

The tridentate Schiff base ligand in the title compound, [V(C(16)H(14)N(2)O(3))(CH(3)O)O], has its O, N and O' atoms spanning three basal positions of the square-based-pyrimidally V(V) atom. The fourth basal site is occupied by a methoxo ligand, which results from a deprotonated methanol solvent molecule, and the oxido ligand occupies the apical position. The hy-droxy H atom forms an intra-molecular O-H⋯N hydrogen bond with an N-atom acceptor site.

(4-Chloro-benzohydrazidato-κN',O)[2-(4-chloro-benzoyl-hydrazinyl-idene-κN,O)-3-phenyl-propionato(2-)-κO]oxidovanadium(V) methanol monosolvate.

The V(V) atom in the title compound, [V(C(7)H(6)ClN(2)O)(C(16)H(11)ClN(2)O(3))O]·CH(3)OH, is N,O-chelated by the benzoyl-hydrazidate anion and O,N,O'-chelated by the (benzoyl-hydrazinyl-idene)propionate dianion. The distorted octa-hedral trans-N(2)O(4) coordination geometry is completed by the vanadyl O atom. The mononuclear and solvent mol-ecules are linked by N-H⋯O and O-H⋯O hydrogen bonds about a center of inversion, generating a dimer.

2-[(4-Methyl-benzo-yl)hydrazono]-propionic acid monohydrate.

In the title compound, C(11)H(12)N(2)O(3)·H(2)O, the water mol-ecule is a hydrogen-bond donor to the double-bond amide and the carbonyl O atoms of two acid mol-ecules; it is also a hydrogen-bond acceptor to the acid -OH and amide -NH- groups. These hydrogen-bonding inter-actions give rise to a layer structure, with the layers parallel to the ab plane.

(Benzohydrazidato-κN',O)-[2-(benzoyl-hydrazono-κN,O)propion-ato-κO]oxido-vanadium(V).

The V(V) atom in the title compound, [VO(C(7)H(7)N(2)O)(C(10)H(8)N(2)O(3))], is N,O-chelated by the benzohydrazidate anion and O,N,O'-chelated by the 2-(benzoyl-hydrazono)propionate dianion. The distorted octa-hedral trans-N(2)O(4) coordination geometry is completed by the vandadyl O atom. Mol-ecules are linked by N-H⋯O hydrogen bonds into a supra-molecular chain structure parallel to [010].

2-[(4-Chloro-benzo-yl)-hydrazono]-propionic acid monohydrate.

In the title compound, C(10)H(9)ClN(2)O(3)·H(2)O, the water mol-ecule is a hydrogen-bond donor to the amide and carbonyl O atoms of two acid mol-ecules; it is also a hydrogen-bond acceptor to the acid OH group and the amide H atom. The hydrogen-bonding inter-actions give rise to a two-dimensional array.

(4-Chloro-benzohydrazidato-κN',O)[2-(4-chloro-benzoyl-hydrazono-κN,O)propionato(2-)-κO]oxidovanadium(V).

In the crystal structure of the title compound, [VO(C(7)H(6)ClN(2)O)(C(10)H(7)ClN(2)O(3))], the V(V) atom is N,O-chelated by the chloro-benzoyl-hydrazidate anion and O,N,O'-chelated by the (chloro-benzoyl-hydrazono)propionate dianion. The distorted octa-hedral trans-N(2)O(4) coordination geometry is completed by the vanadyl O atom. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into a linear chain parallel to [010].