Syntheses,supramolecular structures and properties of six coordination complexes based on 5-sulfosalicylic acid and bipyridyl-like chelates

Six new complexes constructed by 5-sulfosalicylic acid and bipyridyl-like ligands (2,2′-bipy and 1,10-phen), namely [Cu₄(OH)₂(ssal)₂(phen)₄ · 7H₂O] (1), [Cu₄(OH)₂(ssal)₂(bipy)₄ · 2H₂O] (2), [Cd(Hssal)(bipy)] (3), [Cd(HL)₂(phen)₂] (4), [Cr(ssal)(bipy)(H₂O)₂ · 2H₂O] (5) and [Cr(ssal)(phen)₂] (6) (H₃ssal = 5-sulfosalicylic acid, H₂L = p-hydroxybenzenesulfonic acid, bipy = 2,2′-bipy, phen = 1,10-phen) were prepared under hydrothermal conditions and their structures were determined by single-crystal X-ray diffraction. Complexes 1 and 2 are both tetranuclear copper complexes with a stepped topology. In complex 3, a new coordination mode of the Hssal²⁻ group is reported in this work. During the synthetic process of complex 4, in situ decarboxylation of 5-sulfosalicylic acid into p-hydroxybenzenesulfonic acid is involved. Two chromium 5-sulfosalicylates (5 and 6) are reported for the first time. These new complexes display different supramolecular structures by O–H?O, C–H?O hydrogen bonds as well as π?π, C–H?π and O?π interactions. The results of magnetic determination show that ferromagnetic interactions exist in complex 1, however, antiferromagnetic interactions exist in 2.     

Solvothermal syntheses and crystal structures of new Cu(II) complexes with phenylsuccinic acid

Five new Cu(II) complexes [Cu(psa)(phen)] · 3H₂O (1), [Cu(psa)(2bpy)] · 0.5H₂O (2), [Cu(psa)(2bpy)(H₂O)] · 3H₂O (3), [Cu(psa)(4bpy)] · H₂O (4), and [Cu(psa)_0.5(N₃)(2bpy)] (5) (H₂psa = phenylsuccinic acid, phen = 1,10-phenanthroline, 2bpy = 2,2′-bipyridine, and 4bpy = 4,4′-bipyridine) were obtained under solvothermal conditions and characterized by single-crystal X-ray diffraction. Complexes 2 and 3 were formed by one-pot reaction. In complex 2, Cu(II) ion is four-coordinated and locates at a slightly distorted square center. In complex 3, the coordinated water molecule occupies the axial site of Cu(II) ion forming a tetragonal pyramid geometry. Complexes 1 and 3 are of 1D chain structures, and extended into 2D supramolecular network by hydrogen bonds. Complex 2 is of zipper structure, and further assembled into 2D supramolecular network by hydrogen bonds and π–π stacking interactions. Complex 4 is a 3D CdSO₄-like structure with twofold interpenetration, while complex 5 is a dinuclear compound. The different structures of complexes 1–5 can be attributed to using the auxiliary ligands, indicating an important role of the auxiliary ligands in assembly and structure of the title complexes.     

Synthesis and spectral characterization of zinc(II) complexes of N(4)-substituted thiosemicarbazone derived from salicylaldehyde: Structural study of a novel –OH free Zn(II) complex

Five novel zinc(II) complexes of salicylaldehyde 3-hexamethyleneiminyl thiosemicarbazone were synthesized and physico-chemically characterized. The complexes were given the formulae [Zn(HL)₂] (1), [Zn(L)py] (2), [Zn(L)bipy] · 3.5H₂O (3), [Zn(L)phen] · H₂O (4) and [Zn(L)γ-pic] (5). The thiosemicarbazone binds the metal as a dianionic ONS donor ligand in all the complexes, except in 1. Compound 1 is a homoleptic complex with zinc occupying the center of a distorted tetrahedral environment and being coordinated by two azomethine nitrogen and two thiolate sulfur atoms.     

Novel octahedral nickel(II) dithiocarbamates with bi- or tetradentate N-donor ligands: X-ray structures of [Ni(Bzppzdtc)(phen)2]ClO4 · CHCl3 and [Ni(Bz2dtc)2(cyclam)]

A series of novel octahedral nickel(II) dithiocarbamate complexes involving bidentate nitrogen-donor ligands (phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine) or a tetradentate ligand (cyclam = 1,4,8,11-tetraazacycloteradecane) of the composition [Ni(BzMetdtc)(phen)₂]ClO₄ (1), [Ni(Pe₂dtc)(phen)₂]ClO₄ (2), [Ni(Bzppzdtc)(phen)₂]ClO₄ · CHCl₃ (3), [Ni(Bzppzdtc)(phen)₂](SCN) (4), [Ni(BzMetdtc)(bpy)₂]ClO₄ · 2H₂O (5), [Ni(Pe₂dtc)(cyclam)]ClO₄ (6), [Ni(BzMetdtc)₂(cyclam)] (7), [Ni(Bz₂dtc)₂(cyclam)] (8) and [Ni(Bz₂dtc)₂(phen)] (9) (BzMetdtc = N,N-benzyl-methyldithiocarbamate(1-) anion, Pe₂dtc = N,N-dipentyldithiocarbamate(1-) anion, Bz₂dtc = N,N-dibenzyldithiocarbamate(1-) anion, Bzppzdtc = 4-benzylpiperazinedithiocarbamate(1-) anion), have been synthesized. Spectroscopic (electronic and infrared), magnetic moment and molar conductivity data, and thermal behaviour of the complexes are discussed. Single crystal X-ray analysis of 3 and 8 confirmed a distorted octahedral arrangement in the vicinity of the nickel atom with a N₄S₂ donor set. They represent the first X-ray structures of such type complexes. The catalytic influence of complexes 2, 3, 6, and 7 on graphite oxidation was studied and discussed.     

(Amidomethyl)dimethylsilanol hydrohalides: Synthesis, NMR and IR studies. Characteristic features of the electronic structure from high-resolution X-ray study and quantum chemical calculation

(C,O)-chelate silanol hydrohalides RC(O)NHCH₂SiMe₂OH · HHal (2a,b and 5b), and their precursors, (C,O)-chelate chlorosilanes RC(O)NHCH₂SiMe₂Cl (6a,b) and disiloxanes [RC(O)NHCH₂SiMe₂]₂O (8a,b) (R = Me (a), Ph (b); Hal = Cl (2), Br (5)), were obtained by several routes. The original scheme of hydrolysis of the above chlorides was discussed in detail. X-ray analysis has shown that the silanol hydrohalogenides PhC(O)NHCH₂SiMe₂OH · HX (2b and 5b) in the crystal exist in the form of cation-anion pairs [PhC(O)NHCH₂SiMe₂(OH₂)]⁺ · X⁻ (14b · Cl⁻ and 14b · Br⁻) assembled by H-bonds in a 3D framework. The Si atom in the cation has a trigonal bipyramidal configuration with the oxygen atom of the carbonyl group and protonated hydroxyl exo-substituent in axial positions. The endocyclic Si-O bonds are equal with an average of 1.905 Å while the exocyclic Si-O bonds are 1.979 and 2.009 Å, for Hal = Cl and Br, respectively.Quantum chemical calculations have shown that the cation [PhC(O)NHCH₂SiMe₂(OH₂)]⁺ (14b) is stable only in the crystal. Based on a high-resolution X-ray study and a quantum chemical calculation, it was found that the chemical bonding pattern in the OSiO axial fragment of the cation 14b corresponds to a three-centred four electron interaction. The cation 14b should be considered as a silylium cation stabilized by coordinated H₂O molecules rather than a silyloxonium ion.     

Synthesis,structure and biological properties of several binary and ternary complexes of copper(II) with ciprofloxacin and 1,10 phenanthroline

In this study, a new binary complex [Cu(HCip)₂](NO₃)₂ · 6H₂O (1) has been synthesized and then characterized by X-ray structure analyses. In this compound, each ciprofloxacin acts as a bidentate ligand resulting in a crystallographically planar configuration; the nitrate anions are located in apical positions with an axial distance significantly larger than the equatorial distances, which would be consistent with a very weak metal ion interaction due to the Jahn–Teller effect. In addition, both the synthesis and characterization of two new ternary complexes of ciprofloxacin–copper(II)–1,10-phenanthroline, [Cu(phen)(Cip)](NO₃) · 4H₂O (2) and Cu(phen)(HCip)(NO₃)₂ · H₂O (3), have been accomplished. We have also undertaken the single crystal structural determination of 2, in which the ciprofloxacin acts as tridentate bridging ligand; the complex exhibits a five-coordinated motif in a distorted square pyramidal environment around the metal center. The chemical nuclease activity of compounds 2 and 3 has also been studied, revealing that both compounds behave as efficient chemical nucleases in the presence of ascorbate. Mechanistic studies, with various radical oxygen scavengers, indicate that the DNA cleavage reaction is mediated by hydroxyl radicals, singlet oxygen, and the superoxide anion.     

Synthesis,spectral and EPR studies of oxovanadium(IV) complexes incorporating tridentate ONO donor hydrazone ligands: Structural study of one oxovanadium(V) complex

Five oxovanadium(IV) complexes of 2-hydroxy-4-methoxybenzaldehyde nicotinic acid hydrazone (H₂L¹), 2-hydroxy-4-methoxyacetophenone nicotinic acid hydrazone (H₂L²) and a binuclear oxovanadium(V) complex of H₂L² have been synthesized. These complexes were characterized by different physicochemical techniques like electronic, infrared and EPR spectral studies. The complexes [VOL¹]₂ · H₂O (1) and [VOL²]₂ · H₂O (4) are binuclear and [VOL¹bipy] (2), [VOL¹phen] · 1.5H₂O (3) and [VOL²phen] · 2H₂O (6) are heterocyclic base adducts and are EPR active. In frozen DMF at 77 K, all the oxovanadium(IV) complexes show axial anisotropy with two sets of eight line patterns. The complex [VOL² · OCH₃]₂ (5) is an unusual product and has distorted octahedral geometry, as obtained by X-ray diffraction studies.     

Syntheses and characterizations of nine coordination polymers of transition metals with carboxylate anions and bis(imidazole) ligands

Nine new compounds, namely [CuL1(biim-6)] · H₂O (1), [ZnL1(biim-6)] · H₂O (2), [MnL1(biim-6)] · H₂O (3), [MnL1(biim-4)] (4), [Co₂(L2)₂(biim-5)₃ · 6H₂O] · 8H₂O (5), [ZnL3(biim-6)] (6), [ZnL3(biim-5)] (7), [CdL3(biim-5) · 1.5H₂O] · 0.5H₂O (8) and [CdL4(biim-6) · 2H₂O] (9) [where L1 = oxalate anion, L2 = fumarate anion, L3 = phthalate anion, L4 = p-phthalate anion, biim-4 = 1,1′-(1,4-butanediyl)bis(imidazole), biim-5 = 1,1′-(1,5-pentanedidyl)bis(imidazole) and biim-6 = 1,1′-(1,6-hexanedidyl)bis(imidazole)] were successfully synthesized. Compounds 1–3 are isostructural, and display 2D polymeric structures. Compound 4 shows a threefold interpenetrating diamondoid framework. In compound 5, the anions act as counterions, and the metal cations are bridged by bis(imidazole) ligands to form 1D polymeric chains. Compounds 6–9 show 2D polymeric structures. The magnetic properties for 1, 3 and 4 and luminescent properties for 2 and 6–9 are discussed. Thermogravimetric analyses (TGA) for these compounds are also discussed.     

Heteronuclear M(II)-Ln(III) (M = Co, Mn; Ln = La, Pr, Sm, Gd, Dy and Er) coordination polymers: Synthesis, structures and magnetic properties

Thirteen novel 3d-4f heteronuclear coordination polymers based on the pyridine-2,6-dicarboxylic acid (H₂pda) and imidazole ligands, HIm[(pda)₃MLn(Im)₂(H₂O)₂]·3H₂O (Im = imidazole; M = Co, Ln = Pr (1), Gd (2), Dy (3), Er (4); M = Mn, Ln = Pr (5), Sm (6), Gd (7), Dy (8), Er (9)), HIm[(pda)₃CoSm(Im)₂(H₂O)₂]·2H₂O (10), [(Im)₄M(H₂O)₂][(pda)₄La₂(H₂O)₂]·2H₂O (M = Co (11), Mn (12)), and [(pda)₆Co₃Pr₂(H₂O)₆]·6H₂O (13), have been prepared and structurally characterized. X-ray crystallographic analyses revealed that these complexes display four different types of structures. Complexes 1-9 are isostructural, and possess 1-D chain structures constructed by alternately arrayed nine-coordinated Ln(III) (Ln = Pr, Sm, Gd, Dy, Er) and six-coordinated M(II) (M = Mn, Co) ions. Complex 10 exhibits a unique one-dimensional structure, in which two independent chains are parallel viewed down the a-axis and anti-parallel viewed down the c-axis. Complexes 11 and 12 are isostructural and display 1-D homometallic chain structures. Complex 13 is a 3D framework fabricated through PrN₃O₆ and CoO₆ polyhedrons as building blocks. The variable-temperature solid-state dc magnetic susceptibilities of complexes 2, 3, 4, 9 and 13 have been investigated. Antiferromagnetic exchange interactions were determined for these five complexes.     

Axial and equatorial carbene ligands of dimanganese and dirhenium monocarbene complexes: Synthesis, characterisation and structural studies

The binuclear alkoxycarbene complexes [M₂(CO)₉{C(OEt)C₄H₃Y}] (M = Mn, Y = S(1), O(2); Re, Y = S(3), O(4)) were synthesised and characterised, giving axial carbene ligands for the dimanganese complexes, and equatorial carbene ligands for the dirhenium complexes. Aminolysis of these complexes with ammonia and n-propylamine yielded complexes [M₂(CO)₉{C(NHR)C₄H₃Y}] (R = H, M = Mn, Y = S(5), O(6); Re, Y = S(7), O(8); R = propyl, M = Mn, Y = S(9), O(10); Re, Y = S(11), O(12)). For the smaller NH₂-substituted carbene ligands, the X-ray structures determined showed equatorial carbene ligands for both dimanganese and dirhenium complexes, while the NHPr-substituted carbene complexes retained the original configurations of the precursor alkoxy carbene complex, indicating that the steric effects of both the M(CO)₅-fragment and the carbene ligand substituent can affect the coordination site of the carbene ligands of Group VII transition metal complexes in the solid state.     

Syntheses,crystal structures,and magnetic and luminescent properties of a series of lanthanide coordination polymers with chelidamic acid ligand

A series of lanthanide(III) complexes with chelidamic acid ligand, [Ln(C₇H₂NO₅)·3H₂O]_n·nH₂O (Ln = La (1), Y (2), Sm (3), and Nd (4)), [Gd₂(C₇H₂NO₅)₃·4H₂O]_n·2nH₂O (5) and [Ce(C₇H₂NO₅)·1.5H₂O]_n (6), have been synthesized by hydrothermal method and structurally characterized by single-crystal X-ray diffraction. Complexes 1–4 are isostructural and possess 2D framework. Complex 5 contains two different Gd(III) ions linked through carboxylate group to form a 2D framework. Complex 6 exhibits a (4⁴) topology 2D network. The variable-temperature magnetic properties of 3 and 5 have been investigated. Furthermore, the photoluminescent properties of 1, 2, 3, and 5 at room temperature were also studied.     

Zinc(II) complexes derived from di-2-pyridyl ketone N-phenyl-3-semicarbazone: Crystal structures and spectral studies

Six zinc(II) complexes, Zn(HL)Br₂ (1), Zn(HL)Cl₂ (2), ZnL(OAc) (3), ZnLN₃ (4), ZnL₂ (5) and ZnL₂ · H₂O (6), have been synthesized and characterized by different physicochemical techniques. Complex 1 is five coordinated and has a distorted square pyramidal geometry. Complexes 5 and 6 are six coordinated and have distorted octahedral geometries. In complexes 1 and 2, the ligand moieties are coordinated in the neutral form (HL), and in the other complexes they are monoanionic (L⁻).     

Orthopalladation of phosphorus ylides in endo position with bidentate ligands

The ortho-metallated complexes [Pd₂{κ²(C,C)-C₆H₄(PPh₂CHC(O)C₆H₅R}₂(μ-Cl)₂] (R = Ph (1a), NO₂ (1b), Br (1c)) were prepared by refluxing equimolar mixtures of Ph₃PCHC(O)C₆H₅R, (R = Ph, NO₂, Br) and Pd(OAc)₂ in MeOH, followed by an excess of NaCl. The dinuclear complexes (1a-1c) react with silver trifluoromethylsulfonate and bidentate ligands [L = bipy (2,2′-bipyridine), phen (phenanthroline), dppe (bis(diphenylphosphino)ethane), dppp (bis(diphenylphosphino)propane)] giving the mononuclear stabilized orthopalladated complexes in endo position [Pd{κ²(C,C)-C₆H₄(PPh₂CHC(O)R}L](OTf) [R = Ph, L = phen (2a), bipy (3a), dppe (4a), dppp (5a); R = NO₂, L = phen (2b), bipy (3b), dppe (4b), dppp (5b); R = Br, L = phen (2c), bipy (3c), dppe (4c), dppp (5c); OTf = trifluoromethylsulfonate anion]. Orthometalation and ylidic C-coordination are demonstrated by an X-ray diffraction study of 2c and 3c. In the structures, the palladium atom shows a slightly distorted square-planar coordination geometry.     

Syntheses,structures, network topologies and photoluminescence of four Zn(II) and Cd(II) coordination polymers based on 5-carboxyl-1-carboxymethyl-2-oxidopyridinium

5-Carboxyl-1-carboxymethyl-2-oxidopyridinium (H₂CCOP) and a combination of N-donor ligands, such as 4,4′-bipyridine (4,4′-bipy) and 1,10-phenanthroline (phen) with d¹⁰ metal ions Zn(II) and Cd(II) give rise to four coordination polymers, namely, [Zn₂(CCOP)(OH)₂(H₂O)] (1), [Zn(CCOP)(phen)(H₂O)]·H₂O (2), [Cd(CCOP)(H₂O)₂]·3H₂O (3), and [Cd(CCOP)(H₂O)] (4). Polymer 1 features an unusual bilayer motif and forms the final (3,8)-connected 3D topology by hydrogen bonds. Polymer 2 consists of one-dimensional (1D) chains which are further connected with each other via hydrogen bonds to form the final interesting (3,6)-connected rutile network. Polymer 3 is made up of an unusual 2D structure containing cylinder channels in the b axis and features the (4,4)-connected 3D network by hydrogen bonds. Polymer 4 presents an interesting uninodal 4-connected net compared to polymer 3. These four coordination polymers are obtained by evaporation or hydrothermal route and characterized by analytical, spectroscopic, and crystallographic methods. Photoluminescence studies revealed that these four coordination polymers display structure-related fluorescent emission bands (λ_ex = 342 nm) at 361 nm for polymer 1, 404 nm for polymer 2, 367 nm for polymer 3, and 371 nm for polymer 4 in the solid state at room temperature.     

Syntheses,crystal structures and photoluminescence of three coordination polymers with 2,3-pyrazinedicarboxylic acid and N-donor ligands

The reactions between Cd(OAc)₂/Cu(NO₃)₂ and mixed ligands (2,3-pyrazinedicarboxylic acid (pzdc) and N-donor ligands) under different reaction conditions give the three title complexes 1, 2 and 3. There is a (4,8) net 2D network structure and a rectangular grid network structure in the cadmium complexes [Cd(pzdc)(phen)] · H₂O (1) and Cd₂(pzdc)₂(4,4′-bpy)(H₂O)₂ (2), respectively. The complex [Cu₄(pzdc)₄(phen)₂(H₂O)₄] · 10H₂O (3) has a 1D zigzag chain structure. The influences of coordination modes of the pzdc ligand and N-donor ligands on the superstructural diversity have been discussed. Complexes 1 and 2 exhibit strong fluorescent emission bands in the solid state at room temperature. The EPR spectrum of 3 is typical for a square-pyramidal geometry of copper (II) ions.     

Synthesis,structure, and electrochemistry of pyridinecarboxamide cobalt(III) complexes; the effect of bridge substituents on the redox properties

Two series of complexes of the types trans-[Co^III(Mebpb)(amine)₂]ClO₄ {Mebpb²⁻ = N,N-bis(pyridine-2-carboxamido)-4-methylbenzene dianion, and amine = pyrrolidine (prldn) (1a), piperidine (pprdn) (2a), morpholine (mrpln) (3a), benzylamine (bzlan) (4a)}, and trans-[Co^III(cbpb)(amine)₂]X {cbpb²⁻ = N,N-bis(pyridine-2-carboxamido)-4-chlorobenzene dianion, and amine = pyrrolidine (prldn), X = PF₆ (1b), piperidine (pprdn), X = PF₆ (2b), morpholine (mrpln), X = ClO₄ (3b), benzylamine (bzlan), X = PF₆ (4b)} have been synthesized and characterized by elemental analyses, IR, UV–Vis, and ¹H NMR spectroscopy. The crystal structure of 1a has been determined by X-ray diffraction. The electrochemical behavior of these complexes, with the goal of evaluating the effect of axial ligation and equatorial substitution on the redox properties, is also reported. The reduction potential of Co^III, ranging from −0.53 V for (1a) to −0.31 V for (3a) and from −0.48 V for (1b) to −0.22 V for (3b) show a relatively good correlation with the σ-donor ability of the axial ligands. The methyl and chloro substituents of the equatorial ligand have a considerable effect on the redox potentials of the central cobalt ion and the ligand-centered redox processes.     

Investigation on coordination modes of organotin(IV) complexes with 6-thiopurine and related ligands

The organotin(IV) complexes R₂Sn(tpu)₂ · L [L = 2MeOH, R = Me (1); L = 0: R = n-Bu (2), Ph (3), PhCH₂ (4)], R₃Sn(Hthpu) [R = Me (5), n-Bu (6), Ph (7), PhCH₂ (8)] and (R₂SnCl)₂ (dtpu) · L [L = H₂O, R = Me (9); L = 0: R = n-Bu (10), Ph (11), PhCH₂ (12)] have been synthesized, where tpu, Hthpu and dtpu are the anions of 6-thiopurine (Htpu), 2-thio-6-hydroxypurine (H₂thpu) and 2,6-dithiopurine (H₂dtpu), respectively. All the complexes 1-12 have been characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectra analyses. And complexes 1, 2, 7 and 9 have also been determined by X-ray crystallography, complexes 1 and 2 are both six-coordinated with R₂Sn coordinated to the thiol/thione S and heterocyclic N atoms but the coordination modes differed. As for complex 7 and 9, the geometries of Sn atoms are distorted trigonal bipyramidal. Moreover, the packing of complexes 1, 2, 7 and 9 are stabilized by the hydrogen bonding and weak interactions.     

Synthesis,characterization and superoxide dismutase activity of some octahedral nickel(II) complexes

Four new mixed ligand nickel(II) complexes viz., [Ni(tren)(phen)](ClO₄)₂ (1), [Ni(tren)(bipy)](ClO₄)₂ (2), [Ni(SAA)(PMDT)] · 2H₂O (3) and [Ni(SAA)(TPTZ)] (4) (tren = tris(2-aminoethylamine), phen = 1,10-phenanthroline, bipy = 2,2′-bipyridine, SAA = salicylidene anthranilic acid, PMDT = N,N,N′,N″,N″-pentamethyldiethylenetriamine, TPTZ = 2,4,6-tri(2-pyridyl)-1,3,5-triazine) have been synthesized and characterized by means of elemental analysis, spectroscopic, magnetic susceptibility and cyclic voltammetric measurements. Single crystal X-ray analysis of [Ni(tren)(phen)](ClO₄)₂ (1) and [Ni(SAA)(PMDT)] · 2H₂O (3) has revealed the presence of a distorted octahedral geometry. Superoxide dismutase activity of these complexes has also been measured.     

Mononuclear Fe(III) and tetranuclear [Fe(III)Gd(III)]2 complexes with a Schiff-base ligand derived from the o-vanillin: Synthesis, crystal structures and magnetic properties

The mononuclear high-spin iron(III) complexes [Fe(3-MeOsalpn)Cl(H₂O)] (1) and [Fe(3-MeOsalpn)(NCS)(H₂O)]·0.5CH₃CN (2) and the tetranuclear oxo-bridged compound [{Fe(3-MeOsalpn)Gd(NO₃)₃}₂(μ-O)]·CH₃CN (3) [3-MeOsalpn²⁻ = N,N′-propylenebis(3-methoxysalicylideneiminate)] have been prepared and magneto-structurally characterised. The iron(III) ion in 1 and 2 is six-coordinated in a somewhat distorted octahedral surrounding with the two phenolate-oxygens and two imine-nitrogens from the Schiff-base building the equatorial plane and a water (1 and 2) and a chloro (1)/thiocyanate-nitrogen (2) in the axial positions. The neutral mononuclear units of 1 and 2 are assembled into centrosymmetric dinuclear motifs through hydrogen bonds between the axially coordinated water molecule of one iron centre and methoxy-oxygen atoms from the Schiff-base of the adjacent iron atom. The values of the intradimer metal-metal distance within the supramolecular dimers are 4.930 (1) and 4.878 Å (2). The tetranuclear of 3 can be described as two {Fe^III(3-MeOsalpn)} units connected through an oxo-bridge, each one hosting a [Gd^III(NO₃)₃] entity in the outer cavity defined by the two phenolate- and two methoxy-oxygen atoms. The values of the intramolecular Fe?Fe and Fe?Gd distances in 3 are 3.502 and 3.606 Å, respectively. The analysis of the magnetic data of 1-3 in the temperature range 1.9-300 K shows the occurrence of weak intermolecular antiferromagnetic interactions in 1 and 2 [J = −0.76 (1) and −0.75 cm⁻¹ (2) with the Hamiltonian defined as H = −JS_Fe1·S_Fe1] whereas two intramolecular antiferromagnetic interactions coexist in 3, one very strong between the two iron(III) ions (J₁) through the oxo bridge and the other much weaker between the iron(III) and the Gd(III) ions (J₂) across the double phenoxo oxygens [J₁ = −275 cm⁻¹ and J₂ = −3.25 cm⁻¹, the Hamiltonian being defined as H=-J₁S_Fe1·S_Fe1^′-J₂(S_Fe1·S_Gd1+S_Fe1^′·S_Gd1^′)]. These values are analysed in the light of the structural data and compared with those of related systems.