New poly-iron(II) complexes of N4O dinucleating Schiff bases and pseudohalides: syntheses, structures, and magnetic and Mössbauer properties

Six dinuclear ferrous complexes including [Fe2(acpypentO)(O2CMe)(NCS)2] (1), [Fe2(acpypentO)(O2CMe)(NCSe)2] (2), [Fe2(acpypentO)(NCO)3] (3), ([Fe2(acpybutO)(O2CMe)(NCS)2] (5), [Fe2(acpybutO)(O2CMe)(NCO)2] (6), and [Fe2(acpybutO)(O2CMe)(N3)2] (7), one tetranuclear (bis-dinuclear) ferrous compound, [Fe4(acpypentO)2(N3)6] (4), and one mononuclear ferrous compound, [Fe(acpybutOH)(NCS)2] (8), have been prepared, and their structures and magnetic and M?ssbauer properties have been studied (acpybutOH = 1,4-bis[[2-pyridyl(1-ethyl]imino)]butane-2-ol and acpypentOH = 1,5-bis[[2-pyridyl(1-ethyl]imino)]pentane-3-ol). The X-ray diffraction analyses yielded the following results: 1 (C23H26Fe2N6O3S2, monoclinic, P2(1)/n, a = 8.0380(7) A, b = 12.4495(8) A, c = 27.358(2) A, beta = 92.180(10) degrees, V = 2735.7(4) A(3), Z = 4) is a dinuclear species in which the unequivalent high-spin (HS) Fe(II) sites are bridged by the alkoxo oxygen atom of the symmetrical acpypentO- Schiff base and one syn-syn acetato anion; 3 (C22H23Fe2N7O4, triclinic, Ponemacr;, a = 8.4152(10) A, b = 9.1350(10) A, c = 17.666(2) A, alpha = 97.486(14) degrees, beta = 100.026(14) degrees, gamma = 113.510(13) degrees, V = 1195.9(2) A3, Z = 2) is a dinuclear species in which the unequivalent HS Fe(II) sites are bridged by the alkoxo oxygen atom of the symmetrical acpypentO- Schiff base and one end-on NCO anion; 4-MeOH (C39H50Fe4N26O3, triclinic, Ponemacr;, a = 9.1246(11) A, b = 10.2466(11) A, c = 14.928(2) A, alpha = 91.529(15) degrees, beta = 101.078(16) degrees, gamma = 106.341(14) degrees, V = 1309.6(3) A3, Z = 1) is a bis-dinuclear species in which the unequivalent HS Fe(II) sites are bridged by the alkoxo oxygen atom of the symmetrical acpypentO- Schiff base and one end-on N(3)(-) anion, and the symmetry related Fe(II) sites are bridged by two end-on N3- anions; 8-MeOH (C21H26FeN6O2S2, triclinic, Ponemacr;, a = 8.7674(9) A, b = 12.0938(13) A, c = 12.2634(14) A, alpha = 106.685(14) degrees, beta = 93.689(14) degrees, gamma = 108.508(13) degrees, V = 1163.7(2) A3, Z = 2) is a mononuclear species in which the octahedral low-spin (LS) Fe(II) site is in an N6 environment provided by the four N atoms of the protonated asymmetrical acpybutOH Schiff base and two thiocyanato anions. The M?ssbauer spectra of all dinuclear species (1-3 and 5-7), and of the bis-dinuclear compound 4, evidence two distinct HS Fe(II) sites while the M?ssbauer spectra of the mononuclear compound 8 evidence a LS Fe(II) site over the 80-300 K temperature range. The temperature dependence of the magnetic susceptibility was fitted with J = -13.7 cm(-1), D = -1.8 cm(-1), and g = 2.096 for 1; J = 3.0 cm(-1), D(1) = 1.6 cm(-1), E(1) = -0.35 cm(-1) (lambda(1) = 0.22), D2 = - 12.2 cm(-1), E2 = 1.1 cm(-1) (lambda2 = 0.09), and g = 2.136 for 3; and J(1) = - 0.09 cm(-1), J(2) = 15.9 cm(-1), D(1) = 5.7 cm(-1), D(2) = 12.1 cm(-1), and g = 1.915 for 4. The nature of the ground state in 3 and 4 was confirmed by simulation of the magnetization curves at 2 and 5 K. The intradinuclear interaction through the central O(alkoxo) of the acpypentO- ligand and one pseudohalide bridges is ferromagnetic in 3 (end-on cyanato) while it is very weakly antiferromagnetic in 4 (end-on azido). The interdinuclear interaction through two end-on azido bridges (4) is ferromagnetic as expected. In agreement with the symmetry of the two iron sites of complexes 3 and 4, the fits show that D2 (tetragonal pyramid) is larger than D1 (distorted trigonal bipyramid (3) or distorted octahedron (4)).     

Two M(II)-1,5-NDS-dafo supramolecular architectures (M = Cu,Cd): syntheses,structures, and photoluminescence properties

Under hydrothermal conditions, reaction of Cu(II)/Cd(II) salts with 1,5-naphthalenedisulfonate (1,5-NDS) and 4,5-diazafluoren-9-one (dafo) afforded [Cu(dafo)₂(1,5-NDS)]_n (1) and [Cd(dafo)₂(1,5-NDS)]_n (2), respectively. The compounds were characterized by elemental analysis, IR, PXRD, TG-DSC, and single-crystal X-ray diffraction. Both 1 and 2, which are the first M(II)-1,5-NDS-dafo systems, exhibit 3-D supramolecular structures generated by 1-D chains via C–H?O hydrogen bonds and π–π interactions. Solid-state photoluminescence properties of both 1 and 2 were investigated with emission bands at 426–496?nm (λ _ex?=?280, 270?nm for 1 and 2, respectively).     

Two new oxamido-bridged trinuclear complexes [Cu<Subscript>2</Subscript>M] (M = Mn(II), Co(II)): synthesis,structures, and magnetic properties

By using the macrocyclic oxamido-copper complex CuL (H₂L = 2,3-dioxo-5,6:13,14-dibenzo-9,10-(O)cyclohexyl-1,4,8,11-tetraazacyclo-tetradeca-7,12-diene) as precursor, two new trinuclear complexes with the formulas [(CuL)₂Mn(ClO₄)₂] (1) and [(CuL)₂Co(ClO₄)₂] (2) have been synthesized and structurally characterized. H-bonds are found between the molecules, which link adjacent trinuclear units together to form a unique one-dimensional structure. The temperature dependence of the magnetic susceptibility for the complexes was analyzed by means of the Hamiltonian leading to J = −14.66 cm⁻¹ and J = −22.9 cm⁻¹ for 1 and 2, respectively. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Two Cd(ΙΙ) complexes with xanthene-9-carboxylate ligand: syntheses,crystal structures,and emission properties

Two new Cd^II complexes, [Cd(L)₂(CH₃OH)₂]_∞ (1) and [Cd(L)₂(pyz)(H₂O)]_∞ (2), have been prepared by the reaction of xanthene-9-carboxylic acid (HL) and Cd(ClO₄)₂·6H₂O in the presence or absence of pyz co-ligand (L?=?xanthene-9-carboxylate and pyz?=?pyrazine). Their structures were determined by single-crystal X-ray diffraction. Complex 1 possesses a 1-D zigzag chain structure, whereas 2 has a 1-D linear chain that is further assembled into a 2-D network, and then an overall 3-D framework by inter-chain O–H?···?O hydrogen bonds and C–H?···?π supramolecular interactions. Both 1 and 2 are photoluminescent and their emission properties are closely related to their intrinsic structures.     

Synthesis and crystal structure of complexes of manganese(II), cobalt(II), and nickel(II) isothiocyanates with ?-caprolactam

The possibility of ?-caprolactam (CPL) to coordinate to manganese(II), cobalt(II), and nickel(II) rhodanides has been investigated. New complexes trans-[M(CPL)₄(NCS)₂], where M = Mn (I), Co (II), and Ni (III), have been synthesized. The complexes have been studied by chemical analysis and IR spectroscopy. According to X-ray diffraction, complexes are isostructural to each other and crystallize in monoclinic space group P2₁/c, Z = 2. For I: a = 6.9457(2) ?, b = 17.7751(6) 0A, c = 12.8999(4) 0A, ?? = 104.2670(10)°, V = 1543.51(8) ?³, ??_calc = 1.342 g/cm³, R ₁ = 0.0426. For II: a = 6.8925(2) ?, b = 17.8189(8) ?, c = 12.7278(6) ?, ?? = 104.421(2)°, V = 1513.93(11) ?³, ??_calc = 1.377 g/cm³, R ₁ = 0.0280. For III: a = 6.7804(2) ?, b = 18.4631(4) ?, c = 12.4841(3) ?, ?? = 105.2950(10)°, V = 1507.49(7) ?³, ??_calc = 1.382 g/cm³, R ₁ = 0.0273. Structures I?CIII are molecular; the metal atom in each of them coordinates four CPL molecules and two NCS groups via oxygen and nitrogen atoms, respectively.     

Synthesis,structures and magnetic properties of tetranuclear heterometallic complexes [Cu3M] (M = Mn(II) Co(II) and Ni(II)) based on an oxamido-bridged ligand

Transition Metal Chemistry - Three tetranuclear heterometallic coordination compounds of the general formula [(CuL)2M(CuL·CH3OH)](ClO4)2 [(M?=?Mn(for 2), Co(for 3) and Ni(for 4)]...     

Synthesis,crystal structures and magnetic properties of two new nickel(II) complexes with α-amino acid Schiff base

Two nickel(II) complexes [Ni(napgly)(MeOH)] _n (1) and [Ni(napphe)(H₂O)₂(MeOH)] · H₂O (2), where the tridentate Schiff-base ligands H₂napgly and H₂napphe are condensed from 2-hydroxyl-1-naphthaldehyde with glycine and L-phenylalanine, respectively, were prepared and structurally characterized. In 1, two inversion-related Ni(II) ions were bridged by two O atoms from the phenolate groups of two napgly anions, forming a centrosymmetric dimeric unit which was further linked by carboxylate groups to give a two-dimensional network. Magnetic susceptibility studies performed on the complex revealed anti-ferromagnetic coupling between the metal centers. In 2, the crystal structures of the complex displayed a distorted octahedral coordination geometry in which the ONO-donor Schiff base was bonded to the metal. Intermolecular H-bonds linked the compound into a 2-D layer structure.     

Three novel octacyanomolybdate(IV)–M(II) [M = Mn and Cu] bimetallic assemblies: crystal structures and magnetic properties

Synthesis, structure characterization, and magnetic properties of three novel cyano-bridged complexes {[Mn^II(bpy)(DMF)₂]₂[Mo^IV(CN)₈]·1.5H₂O} _n (1), [Cu^II(L)]₂[Mo^IV(CN)₈]·6.75H₂O (2), and [Mn^II(bpy)₂]₄[Mo^IV(CN)₈]₂·4MeOH·4H₂O (3) (where DMF = N,N′-dimethylformamide; bpy = 2,2-bipyridine and L = 1,3,6,8,11,14-hexaazatricyclo[12.2.1.1^8,11]octadecane) have been studied. The X-ray single-crystal structure reveals that 1 is a cyanide-bridged 1D infinite chain with the alternating of Mn^II(bpy)(DMF)₂ and Mo^IV(CN)₈ moieties. The neighboring chains interact with each other by hydrogen bonding to form a sheet-like network, and the layers further extend to a 3D network due to the face-to-face π···π stack interactions. For 2, the Mo^IV center adopts a distorted square antiprism coordination environment, while the Cu^II center adopts a distorted square pyramidal geometry. The weak Mo–CN···Cu interactions between neighboring molecules lead to a 2D network structure of 2. For 3, basic structural unit is centrosymmetric and contains four Mn^II centers bridged by two octacyanomolybdate(IV). Here, their magnetic properties have also been studied. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis,crystal structures,and properties of two heterometallic Cu(II)–M(II) (M = Zn,Ni) oxamidato-bridged coordination complexes

Two heterometallic coordination complexes, {[Cu(aeop)Zn(H₂O)₃]₂?·?3H₂O} _n (1) and [Cu(aeop)Ni(H₂O)₄]?·?4H₂O (2) (H₄aeop?=?N-(2-aminoterephthalic acid)-N′-(1,3-propanediamine)oxamidate), have been synthesized and characterized by elemental analyses, IR, UV spectroscopy, thermogravimetric analysis, and X-ray crystal diffraction. Complex 1 features a 1-D chain constructed from neutral tetranuclear units. Complex 2 is a neutral binuclear complex. Through intermolecular hydrogen-bonding interactions, 2 gives a 3-D network structure. The variable temperature magnetic susceptibility measurements (2–300?K) of 2 show a pronounced antiferromagnetic interaction between the copper(II) and nickel(II), and the exchange integral J is equal to ?42.7?cm^?1.     

Synthesis,crystal structures,and magnetic properties of cobalt(II) and nickel(II) complexes of 2,2′-bipyridine-6,6′-dicarboxylate: three three-dimensional networks formed via hydrogen bonding interactions

Three Co(II) and Ni(II) complexes, namely [Co(bpdc)(H₂O)₂] (1), [Ni(bpdc)(H₂O)₂] (2), and [Co₂(bpdc)₂(prz)_0.5(H₂O)₃]·0.5H₂O (3) (H₂bpdc = 2,2′-bipyridine-6,6′-dicarboxylic acid and prz = piperazine), have been synthesized from H₂bpdc and the corresponding metal salts under hydrothermal conditions. The complexes were characterized by physico-chemical and spectroscopic methods, as well as by X-ray crystallography. Compounds 1 and 2 both consist of neutral mononuclear molecules, of [Co(bpdc)(H₂O)₂] and [Ni(bpdc)(H₂O)₂], respectively. Compound 3 consists of a mononuclear molecule of [Co(bpdc)(H₂O)₂] and a binuclear molecule of [Co₂(bpdc)₂prz (H₂O)₂]. The discrete neutral complexes 1–3 further extend their structures into three-dimensional supramolecular architectures by intermolecular O–H⋯O and C–H⋯O hydrogen bonds as well as π–π stacking interactions. Magnetic susceptibility measurements show that complex 3 exhibits weak ferromagnetic interactions between the two Co(II) ions bridged by the prz ligand, with C = 5.41 cm³ mol⁻¹ K and θ = +27.6 K, respectively.     

One-dimensional cyanide-bridged Cr(III)–Cu(II) complexes: synthesis,crystal structures and magnetic properties

Using two trans-dicyanidechromium(III) precursors K[Cr(bpdmb)(CN)₂] (bpdmb^2? = 1,2-bis(pyridine-2-carboxamido)-4,5-dimethyl-benzenate), K[Cr(bpClb)-(CN)₂] (bpClb^2? = 1,2-bis(pyridine-2-carboxamido)-4-chloro-benzenate) and one Cu(II) complex of a 14-membered macrocycle as ancillary organic ligand as assembling segments, two one-dimensional cyanide-bridged Cr^III–Cu^II complexes {{[Cu(cyclam)][Cr(bpdmb)(CN)₂]}ClO₄} _n ·nCH₃OH·nH₂O (1) and {{[Cu(cyclam)][Cr(bpClb)(CN)₂]}ClO₄} _n ·nCH₃OH (2) (cyclam = 1,4,8,11-tetraazacyclotetradecane) have been synthesized and characterized by elemental analysis, IR spectroscopy and X-ray structure determination. Single X-ray diffraction analysis shows that their similar one-dimensional cationic single-chain structures consist of alternating units of [Cu(cyclam)]²⁺ and [Cr(bpdmb)(CN)₂]^?/[Cr(bpClb)(CN)₂]^? with free ClO₄ ^? as balancing anions. Investigations of the temperature dependences of magnetic susceptibility and the field-dependent magnetization reveal that both complexes have overall ferromagnetic coupling between the neighboring Cr(III) and Cu(II) centers through the bridging cyanide groups.     

Synthesis,crystal structures,and magnetic properties of three K[M(bpb)(CN)2]-based trinuclear sandwich-like heterobimetallic M(III)–Ni(II) (M = Fe,Cr, Co) complexes

Three trinuclear sandwich-type cyanide-bridged M^III–Ni^II complexes, {[Ni(cyclm)[Fe(bpb)(CN)₂]₂}·8H₂O (1), {[Ni(cyclm)[Cr(bpb)(CN)₂]₂}·2H₂O (2), and {[Ni(cyclm)[Co(bpb)(CN)₂]₂}·CH₃OH·2H₂O (3) (cyclm?=?1,4,8,11-tetraazacyclotetradecane), have been synthesized using K[M(bpb)(CN)₂] (M?=?Fe, Cr, Co; bpb?=?1,2-bis(pyridine-2-carboxamido)benzenate) as building block and one Ni(II) compound containing a 14-membered macrocycle ring as assembling segment. All the complexes have been characterized by elemental analysis, IR spectroscopy, and X-ray structure determination. Single X-ray diffraction analysis shows similar sandwich-like structures, in which the two cyanide-containing building blocks are monodentate through one of their two cyanides, coordinated face to face to the central Ni(II). Investigation of the magnetic properties of 1 and 2 reveals ferromagnetic magnetic coupling between the neighboring Fe(III)/Cr(III) and Ni(II) through the bridging cyanide. A best-fit to the magnetic susceptibilities of 1 and 2 based on the trinuclear M₂Ni model leads to magnetic coupling constants J?=?5.47(1)?cm^?1 for 1 and J?=?6.37(2)?cm^?1 for 2.     

β-diketone complexes of manganese(II), cobalt(II), nickel(II) and palladium(II)

Summary The reactions of manganese(II), cobalt(II) and nickel(II) acetates (1 mole) with antipyrine-4-azo--ethylcyanoacetate (HL¹) and antipyrine-4-azo--acetylacetone (HL²) (1 mole) produce complexes of the M(L)₂ type. K₂PdCl₄ (1 mole) reacts with HL¹ and HL² (1 mole) to yield complexes of the general formula PdLCl, the ligands behaving as monobasic tridentates. The electronic spectral and magnetic data show the complexes to be high-spin octahedral, whereas the palladium(II) complexes are diamagnetic square planar. The complexes were characterized by elemental analyses, conductance measurements and i.r. and electronic spectra as well as magnetic susceptibility measurements and thermal (t.g.a. and d.t.a.) analysis.Nuclear Material Authority.     

Four tri-spin lanthanide–nitronyl nitroxide (LnIII = GdIII,DyIII, ErIII,and HoIII) complexes: syntheses,structures, and magnetic properties

Four radical–Ln(III)–radical complexes, [Ln(hfac)₃(NITPhSCH₃)₂] (Ln?=?Gd (1), Dy (2), Er (3), Ho (4); hfac?=?hexafluoroacetylacetonate; NITPhSCH₃?=?4′-thiomethylphenyl-4,4,5,5tetramethyl-imidazoline-1-oxyl-3-oxide), have been synthesized, and structurally and magnetically characterized. The X-ray crystal structures show that the structures of the four complexes are similar, consisting of isolated molecules in which Ln(III) ions are coordinated by six oxygen atoms from three hfac and two oxygen atoms from nitronyl radicals. The temperature dependencies of magnetic susceptibilities for the four complexes show that in the Gd(III) complex, ferromagnetic interactions between Gd(III)–radical and antiferromagnetic interactions between the radicals coexist with J _Rad–Gd?=?1.09?cm^?1, J _Rad–Rad?=??1.85?cm^?1.     

Two isomorphous Mn(II) and Co(II) 5-amino-tetrazolate coordination polymers with magnetic Δ-chains: crystal structures and magnetic properties

Two Co(II) and Mn(II) coordination polymers, which have been synthesized under hydrothermal conditions, are isomorphous with magnetic Δ-chains containing trinuclear triangular [M(3)(μ(3)-OH)] clusters. The Δ-chains are bridged by isonicotinic spacers to generate a two-dimensional scalariform layer structure. Magnetic investigations indicate that Co(II) compound exhibits not only spin canting but also metamagnetic behaviors, while only spin-canted antiferromagnetic behaviors was observed in Mn(II) compound.     

Syntheses,crystal structures and magnetic properties of heteronuclear bimetallic compounds of [Cu(pdc)2][M(H2O)5]·2H2O [M=Ni(II), Co(II), Mn(II); pdc=2,6-pyridinedicarboxylato]

The complexes [M(H₂O)₅][Cu(pdc)₂]·2H₂O [M=Ni(II) 1, Co(II) 2, Mn(II) 3; pcd=2,6-pyridinedicarboxylato] are prepared and their crystal structures, magnetic susceptibilities and UV-Visible properties reported. In all cases, the Cu(II) ion occupies the chelating site in the pdc ligand, while the M(II) occurs as a pentaaqua ion bridged to the [Cu(pdc)₂] moiety through a carboxylate as demonstrated by both UV-Visible spectroscopy and X-ray diffraction. Single crystal X-ray diffraction shows the three complexes to be isostructural. Weak antiferromagnetic interactions between the metal ions are observed in 1 and 3, while the magnetic behavior of 2 is dominated by single ion anisotropy.     

Self-assembled supramolecular M9 (Mn(II), Fe(III), Zn(II)), M5 (Fe(III)), and [M3]2 (Pb(II)) complexes: structural,magnetic, and Mössbauer properties

The tritopic ligand 2poap self-assembles in the presence of Zn(NO(3))(2) and Fe(NO(3))(3) to form homoleptic [3 x 3] nonanuclear M(9) (M = Zn(II), Fe(III)) square grid structures and with Pb(ClO(4))(2) to form a dimerized linear trinuclear [Pb(3)](2) structure. Cl2poap and Cl2poapz form self-assembled homoleptic [3 x 3] Mn(II)(9) square grids with Mn(ClO(4))(2) and Mn(NO(3))(2), respectively, but an unusual incompletely metalated Fe(III)(5) square grid is formed on reaction of Cl2poap with Fe(ClO(4))(3). X-ray structures are reported for [Mn(9)(Cl2poap-2H)(6)](ClO(4))(6).10H(2)O (3), [Mn(9)(Cl2poapz-2H)(6)] (NO(3))(6).22H(2)O (4), [Zn(9)(2poap-2H)(3)(2poap-H)(3)](NO(3))(9).24H(2)O (5), [Pb(3)(2poap-2H) (ClO(4))(4)](2).8H(2)O (6), and [Fe(5)(Cl2poap-H)(6)](ClO(4))(9).34.5H(2)O (7). Compound 3 crystallized in the monoclinic system, space group P(-)1, with a = 18.179(1) A, b = 18.857(1) A, c = 25.871(2) A, alpha = 70.506(2) degrees, beta = 86.440(1) degrees, gamma = 75.175(2) degrees, and z = 2. Compound 4 crystallized in the monoclinic system, space group P(-)1, with a = 16.900(2) A, b = 20.02393) A, c = 25.663() A, alpha = 84.743(3) degrees, beta = 84.885(2) degrees, gamma = 67.081(2) degrees, and z = 2. Compound 5 crystallized in the monoclinic system, space group P(-)1, with a = 18.482(1) A, b = 18.774(1) A, c = 28.112(2) A, alpha = 104.020(1) degrees, beta = 97.791(1) degrees, gamma = 117.036(1) degrees, and z = 2. Compound 6 crystallized in the monoclinic system, space group P(-)1, with a = 10.0513(6) A, b = 11.0958(6) A, c = 17.334(1) A, alpha = 100.932(1) degrees, beta = 100.387(1) degrees, gamma = 94.565(1) degrees, and z = 2. Compound 7 crystallized in the monoclinic system, space group P(-)1, with a = 19.164(1) A, b = 19.587(2) A, c = 26.673(2) A, alpha = 76.430(2) degrees, beta = 78.834(2) degrees, gamma = 64.973(1) degrees, and z = 2. Compound 3 exhibits intramolecular antiferromagnetic exchange within the nonanuclear [Mn(9)(mu-O)(12)] grid structure (J = -4.6 cm(-1)), while the analogous nonanuclear complex [Fe(9)(2poap-2H)(6)](NO(3))(15).18H(2)O (8) is dominated by intramolecular antiferromagnetic coupling at high temperatures but exhibits a low-temperature feature indicative of additional ferromagnetic interactions. The isolated pentanuclear Fe(5) [4 + 1] square grid in 7, with distant Fe-Fe bridging, exhibits very weak antiferromagnetic coupling (J = -0.2 cm(-1)). M?ssbauer spectroscopy data are consistent with high-spin Fe(III)(9) and Fe(III)(5) structures.     

Copper(II), nickel(II), cobalt(II) and oxovanadium(IV) complexes of substituted β-hydroxyiminoanilides

Complexes of the general formula, ML₂ [M = Cu^II, Ni^II, Co^II and OV^IV; L = 1,2,3,5,6,7,8,8a-octahydro-3-hydroxyimino-N-(4-X-phenyl)-l-phenyl-5-(phenylmethylene)-2-naphthalenecarboxamide (X = H, Me, OMe, Cl)] have been prepared and characterized on the basis of elemental analysis, magnetic moments and i.r., e.p.r. and electronic spectra. These metal complexes contain the N₄ chromophore with the ligand coordinating through nitrogens of the azomethine and deprotonated anilide functions. C.v. measurements indicate that the copper(II) complexes are quasi-reversible in acetonitrile solution. Square planar and square pyramidal structures are assigned respectively to the copper(II) and oxovanadium(IV) complexes, whereas tetrahedral geometry is assigned to the nickel(II) and cobalt(II) complexes. Deprotonated anilide nitrogen is involved in coordination and the presence of an electron-donating group para to the anilide function decreases the ΔE values of the d–d transitions while the value is found to increase when electron-withdrawing groups are substituted. Line spacing in the e.p.r. spectra of the copper(II) and oxovanadium(IV) complexes increases when methyl group is para to the anilide group, and decreases when this group is replaced by methoxy or chloro. The ν(C–N) of the anilide group and the ν(C-N) of the azomethine function of the oxime metal complexes are metal-sensitive and the blue shift for the above stretching frequencies follows the order: copper(II) > oxovanadium(IV) > nickel(II) ≈ cobalt(II). This revised version was published online in June 2006 with corrections to the Cover Date.