Synthesis, structural characterization and electrochemistry of C,N-chelated organotin(IV) dicarboxylates with ferrocenyl substituents

A set of C,N-chelated organotin(IV) ferrocenecarboxylates, [L^CN(n-Bu)Sn(O₂CFc)₂] (1), [(L^CN)₂Sn(O₂CFc)₂] (2), [L^CN(n-Bu)Sn(O₂CCH₂Fc)₂] (3), [L^CN(n-Bu)Sn(O₂CCH₂CH₂Fc)₂] (4), [L^CN(n-Bu)Sn(O₂CCHCHFc)₂] (5), [L^CN(n-Bu)Sn(O₂CfcPPh₂)₂] (6), [(L^CN)₂Sn(O₂CfcPPh₂)₂] (7), and [L^CN(n-Bu)₂Sn(O₂CFc)] (8) (L^CN = 2-(N,N-dimethylaminomethyl)phenyl, Fc = ferrocenyl and fc = ferrocene-1,1′-diyl) has been synthesized by metathesis of the respective organotin(IV) halides and carboxylate potassium salts and characterized by multinuclear NMR and IR spectroscopy. The spectral data indicated that the tin atoms in diorganotin(IV) dicarboxylates bearing one C,N-chelating ligand (1 and 3-6) are seven-coordinated with a distorted pentagonal bipyramidal environment around the tin constituted by the n-butyl group, the chelating L^CN ligand and bidentate carboxylate. Compounds 2 and 7 possessing two chelating L^CN ligands comprise octahedrally coordinated tin atoms and monodentate carboxylate donors, whereas compound 8 assumes a distorted trigonal bipyramidal geometry around tin with the carboxylate binding in unidentate fashion. The solid state structures determined for 1⋅C₆D₆ and 2 by single-crystal X-ray diffraction analysis are in agreement with spectroscopic data. Compounds 1, 3-5, and 8 were further studied by electrochemical methods. Whereas the oxidations of ferrocene units in bis(carboxylate) 2 and monocarboxylate 8 proceed in single steps, compound 1 undergoes two closely spaced one-electron redox waves due to two independently oxidized ferrocenyl groups. The spaced analogues of 2, compounds 3-5, again display only single waves corresponding to two-electron exchanged.     

Synthesis, characterization and hydrolytic behavior of new bis(2-pyridylthio)acetate ligand and related organotin(IV) complexes

The new sodium bis(2-pyridylthio)acetate ligand, Na[(pyS)₂CHCO₂], has been prepared in ethanol solution using 2-mercaptopyridine, dibromoacetic acid and NaOH. New mono- and di-organotin(IV) derivatives containing the anionic bis(2-pyridylthio)acetate have been synthesized from reaction between SnR_nCl_4−n (R = Me, Ph and ⁿBu, n = 1-2) acceptors and Na[(pyS)₂CHCO₂]. Mono-nuclear complexes of the type {[(pyS)₂CHCO₂]R_nSnCl_4−n−1} have been obtained and characterized by elemental analyses, FT-IR, ESI-MS, multinuclear (¹H and ¹¹⁹Sn) NMR spectral data and X-ray crystallography. ESI-MS spectra of methanol solution of the complexes show the existence of hydrolysed species. Attempts to crystallize the dimethyltin(IV) derivative (3), from acetonitrile solution yield the dimeric dicarboxylatotetramethyldistannoxane (8), which was characterized by single crystal diffraction analysis.     

Synthesis and structural characterization of organotin(IV) compounds derived from the self-assembly of hydrazone Schiff base series and various alkyltin salts

Reactions of pyruvic acid hydrazone series [pyruvic acid thiophenecarbonyl hydrazone (L1), pyruvic acid 4-hydroxybenzoylhydrazone (L2), pyruvic acid salicyloylhydrazone (L3), pyruvic acid benzoylhydrazone (L4)], or salicylaldehyde hydrazone Schiff base ligand [salicylaldehyde isonicotinoylhydrazone (L5)] with different alkyltin salts result in six new organotin(IV) compounds, {(n-Bu)₂Sn[2-SC₄H₃CON₂C(CH₃)CO₂](HOC₃H₇-i)}₂ (1), [{(n-Bu)₂SnCl(O)(n-Bu)₂ Sn(O)[C₆H₄CON₂C(CH₃)CO₂]Sn(n-Bu)₂(HOCH₃)}₂]_∞ (2), {(o-ClBz)₂Sn[4-HOC₆H₄CON₂C(CH₃) CO₂] (HOC₂H₅)}₂ (3), {(n-C₈H₁₇)₂Sn[2-HOC₆H₄CON₂C(CH₃)CO₂](H₂O)}₂ (4), {(n-Bu)₂Sn[C₆H₅ CON₂C(CH₃)CO₂][HOSn(n-Bu)₃]}₂ (5), and {[(n-C₄H₉)SnCl₂]⁻[4-NHC₅H₄CON₂CH (C₆H₄O-2)]⁺ (6), which have been characterized by single crystal X-ray diffraction, elemental analysis, IR, ¹H and ¹¹⁹Sn NMR. In compounds 1, 3, 4, weak-bridged dimers are found, in which the two tin atoms are linked by a pair of monodentate bridges. Each pyruvic acid hydrazone ligand serves as an enolic tridentatic ligand. Compound 2 contains dimeric units of {Sn₆(L2)₂(n-Bu)₆(HOCH₃)₂} that are further connected by two pairs of monodentate bridges into an 1D weak-bridged polymeric chain, in which there also exists a fascinating dichlorodistannoxane ladder structure. Studies show that the bulk and steric hindrance of the alkyl groups and the coordinated solvent molecule bonding to Sn center have little effect on the geometry of the weak-bridge for compounds 1-4. A similar weak-bridged dimeric structure is also found in compound 5; in this case, however, there is no coordinated solvent molecule and the corresponding coordination site is replaced by the trialkyltin hydroxide. Compound 6 exhibits a rare 1D supermolecular chain constructed from the zwitterionic {Sn(L5)(n-Bu)Cl₂} units connected by the intermolecular N-H?Cl hydrogen bonds. The thermal stability of compound 1 was also studied.     

Syntheses and crystal structures of mononuclear,tetranuclear and hexanuclear organotin compounds with derivatives of p -aminobenzoic acid

Four organotin(IV) compounds, [Bu₆Sn₆O₆(L¹)₆] (1), [Bu₆Sn₆O₆(L²)₄(L³)₂] (2), [Bu₈Sn₄O₂(L²)₄] (3) and [Ph₃Sn(L²)] (4), were obtained by reactions of BuSnOH, Bu₂SnO and Ph₃SnOH with 4-((6-chloropyridin-3-yl)methylamino)benzonic acid (HL¹), 4-((pyridin-2-yl)methylamino)benzonic acid (HL²) and p-aminobenzoic acid (HL³). 1 is a hexameric cluster, existing in a drum-like structure with prismatic Sn₆O₆ core. Compound 2 is a mixed drum, containing two kinds of carboxylic acid anions. Compound 3 possesses a Sn₄O₄ ladder structure. In 2 and 3, two-dimensional supramolecular structures are formed by the intermolecular hydrogen-bonding interactions. Compound 4 is a monomer with a dimer formed through π–π stacking between adjacent L² anions. Compounds 1–4 were characterized by elemental analyses and IR spectra.     

Synthesis and structural characterization of organotin(IV) carboxylates based on different heterocyclic substituents

Six novel organotin(IV) carboxylates have been successfully synthesized, namely, the polymer (C₆H₅)₃Sn(L1)_∞ (1) [HL1 = 4-imidazolyl benzoic acid], the mononuclear (C₆H₅)₃Sn(L2) (2) [HL2 = 4-pyrazolylbenzoic acid], (C₆H₅)₃Sn(L3)·CH₃OH (3) [HL3 = 4-triazolylbenzoic acid] and (C₆H₅)₃Sn(L4) (4) [HL4 = 4-tetrazolyl benzoic acid] and the tetranuclear [(n-Bu₂Sn)₄(L2)₂O₂(OCH₃)₂] (5) and [(n-Bu₂Sn)₄(L3)₂O₂(OCH₃)₂] (6). X-ray diffraction analyses show 1D infinite chain of polymer 1, single molecular structures of isomorphous complexes 2 and 4, single molecule structures of complex 3 containing solvent CH₃OH molecule and similar ladder-type structures of complexes 5 and 6. The photoluminescence of ligands and 1-6 were also measured in the solid state at room temperature.     

Synthesis,characterization, and antibacterial activity of organotin(IV) complexes with 2-hydroxyacetophenone thiocarbohydrazone

Six new organotin(IV) complexes were synthesized by direct reaction of RSnCl₃ (R?=?Me, Bu and Ph) or R₂SnCl₂ (R?=?Me, Bu and Ph) and 2-hydroxyacetophenone thiocarbohydrazone [H₂APTC] under purified nitrogen in the presence of base in 1?:?2?:?1 molar ratio (metal: base: ligand). Complexes 2–7 have been characterized by elemental analyses, molar conductivity, UV-Visible, IR and ¹H NMR spectral studies. Complexes 2–7 are non-electrolytes. The molecular structure of [Me₂Sn(APTC)]?·?(C₂H₅OH) (5) has been determined by X-ray diffraction analysis. The thiocarbohydrazone ligand (1) and 2–7 have been tested for antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhi and Enterococci aeruginosa.     

Synthesis, characterization and biological activities of some new organotin(IV) derivatives: Crystal structure of [(Sn Ph3) (OOCC6H4OH)] and [(SnMe3)2 (OOC)2C6Cl4 (DMSO)2]

Some new organotin(IV) carboxylates 1-3 of 2-hydroxybenzoic acid (L_A) and 4-6 of 2,3,4,5-tetrachloro-6-(methoxycarbonyl) benzoic acid (L_B) have been synthesized, respectively, by the esterification of triorganotin oxide/hydroxide with the corresponding acids in an appropriate mole ratios. Multinuclear NMR (¹H, ¹³C and ¹¹⁹Sn), IR and X-ray crystallographic studies were carried out to elucidate their structures both in solution and in solid state. The X-ray crystallographic data for 3 was recollected at low temperature. The compound 4 was dissolved in DMSO and a new compound 4 · 2DMSO [(SnMe₃)₂(OOC)₂C₆Cl₄(DMSO)₂] was crystallized out. The structure shows that two Sn moieties are attached to the ligand (L_B) through two carboxylic groups. The two molecules of DMSO are coordinated to each of the Sn atoms via oxygen atom to terminate the conventional polymeric chain of trimethyl carboxylates to a discrete molecule, having trigonal bipyramidal geometry around the Sn atoms. Some of the synthesized compounds exhibited significant antifungal activities and have a potential to be used as drugs.     

Structural chemistry of mononuclear, tetranuclear and hexanuclear organotin(IV) carboxylates from the reaction of di-n-butyltin oxide or diphenyltin oxide with rhodanine-N-acetic acid

Three new organotin(IV) carboxylates, {[n-Bu₂Sn(O₂CC₄H₄NOS₂)]₂O}₂ (1), n-Bu₂Sn(O₂CC₄H₄NOS₂)₂ (2) and [PhSn(O)O₂CC₄H₄NOS₂]₆ · 3H₂O (3) were synthesized by the reaction of di-n-butyltin/diphenyltin oxide and rhodanine-N-acetic acid. The complexes 1-3 are characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR and X-ray crystallography diffraction analyses. The complex 1 has a tetranuclear structure based on a planar four-membered Sn₂O₂ ring, while complex 2 is a hexa-coordinated monomer. As for complex 3, it adopts the hexameric drum-shaped structure. The supramolecular structure of 1 has been found to consist of one-dimensional molecular chain built up by intermolecular non-bonded S?O interactions. The salient feature of the supramolecular structure of complex 2 is that of a one-dimensional polymer, in which intermolecular Sn?O, S?O and S?S interactions are recognized.     

Synthesis, characterization and structural studies of diorganotin(IV) complexes with Schiff base ligand salicylaldehyde isonicotinylhydrazone

Eight diorganotin(IV) complexes of salicylaldehyde isonicotinylhydrazone (H₂SalN) R₂Sn(SalN) R = t-Bu 1, Ph 2, PhCH₂3, o-ClC₆H₄CH₂4, p-ClC₆H₄CH₂5,m-ClC₆H₄CH₂6,o-FPhCH₂7, p-FC₆H₄CH₂8 were prepared. All complexes 1-8 have been characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR analyses. The crystal structures of H₂SalN and complex 1 were determined by X-ray crystallography diffraction analyses. Studies show that H₂SalN is a tridentate planar ligand. For complex 1, the tin atom lies in this plane and forms a five- and six-membered chelate ring with the tridentate ligand. A comparison of the IR spectra of the ligand with those of the corresponding complexes, reveals that the disappearance of the bands assigned to carbonyl unambiguously confirms that the ligand coordinate with the tin in the enol form.     

Synthesis and characterization of new organotin(IV) complexes with polyfunctional ligands

New mono-, di- and tri-organotin(IV) derivatives containing the neutral bis(2-pyridylthio)methane ligand, [(pyS)₂CH₂] and tris(2-pyridylthio)methane ligand, [(pyS)₃CH] have been synthesized from reaction with SnR_nCl_4−n (R = Me, ⁿBu, Ph and Cy, n = 1-3) acceptors. Mono-nuclear adducts of the type {[(pyS)₂CH₂]R_nSnCl_4−n} and {[(pyS)₃CH]R_nSnCl_4−n} have been obtained and characterized by elemental analyses, FT-IR, ESI-MS, multinuclear (¹H and ¹¹⁹Sn) NMR spectral data. The ¹H and ¹¹⁹Sn NMR and ESI-MS data suggest for the triorganotin(IV) derivatives a complete dissociation of the compounds in solution. The mono- and di-organotin(IV) derivatives show a greater stability in solution, and their spectroscopic data are in accordance with the existence of six-coordinated RSnCl₃N₂ or R₂SnCl₂N₂ species.     

Synthesis and characterization of pentagonal bipyramidal organotin(IV) complexes of 2,6-diacetylpyridine Schiff bases of S-alkyl- and aryldithiocarbazates

New organotin(IV) complexes with empirical formula Sn(SNNNS)R₂, where SNNNS is the dianionic form of 2,6-diacetylpyridine Schiff bases of S-methyldithiocarbazate (H₂dapsme) or S-benzyldithiocarbazate (H₂dapsbz) and R = Ph or Me, have been prepared and characterized by IR, UV-Vis, NMR and Mössbauer spectroscopic techniques and conductance measurements. The molecular structures of the Sn(dapsme)R₂ (R = Ph and Me) have been determined by single crystal X-ray diffraction techniques. Both complexes have a distorted pentagonal-bipyramidal geometry in which the tin is coordinated by a dinegatively charged pentadentate chelating agent via pyridine nitrogen, two azomethine nitrogens, and two thiolate sulfurs. The five donors (N₃S₂) provided by the Schiff base occupy the equatorial plane close to a pentagonal planar array while the carbanion ligands occupy axial sites.     

Antimicrobial studies of newly synthesized organotin(IV) complexes of dihydrobis(2-mercaptothiazolinyl)borate

Four organotin(IV) complexes of dihydrobis(2-mercaptothiazolinyl)borate were synthesized and characterized by elemental analysis and spectroscopic techniques (IR, ¹H-NMR, ¹³C-NMR, ¹¹B-NMR, and ¹¹⁹Sn-NMR). All the compounds were screened against bacterial, fungal, and cyanobacterial strains. Among the complexes, triorganotin(IV) complexes show better inhibition growth as compared to diorganotin(IV) complexes.     

Syntheses, characterization and crystal structures of di- and triorganotin (IV) derivatives with 6-amino-1,3,5-triazine-2,4-dithiol

A series of organotin (IV) complexes with 6-amino-1,3,5-triazine-2,4-dithiol of the type [(R_nSnCl_4−n)₂ (C₃H₂N₄S₂)] (n = 3: R = Me 1, n-Bu 2, PhCH₂3, Ph 4; n = 2: R = Me 5, n-Bu 6, PhCH₂7, Ph 8) have been synthesized. All the complexes 1-8 have been characterized by elemental analysis, IR, ¹H and ¹³C NMR spectra. Among them complexes 1, 4, 5 and 8 have also been characterized by X-ray crystallography diffraction analyses, which revealed that the tin atoms of complexes 1, 4, 5 and 8 are all five-coordinated with distorted trigonal bipyramid geometries.     

Structure of N,C,N-chelated organotin(IV) fluorides

The set of starting tri-, di- and monoorganotin(IV) halides containing N,C,N-chelating ligand (L^NCN = {1,3-[(CH₃)₂NCH₂]₂C₆H₃}⁻) has been prepared (1-5) and two compounds structurally characterized ([L^NCNPh₂Sn]⁺I₃⁻ (1c), L^NCNSnBr₃ (5)) in the solid state. These compounds were reacted with KF with 18-crown-6, NH₄F or L^CNnBu₂SnF to give derivatives containing fluorine atom(s). Triorganotin(IV) fluorides L^NCNMe₂SnF (2a) and L^NCNnBu₂SnF (3a) revealed monomeric structural arrangement with covalent Sn-F bond both in the coordinating and non-coordinating solvents, except the behaviour of 3a that was ionized in the methanol solution at low temperature. The products of fluorination of L^NCNSnPhCl₂ (4) and 5 were described by NMR in solution as the ionic hypervalent fluorostannates or the oligomeric species reacting with chloroform, methanol or moisture to zwitterionic monomeric stannate L^NCN(H)⁺SnF₄⁻ (5c), which was confirmed by XRD analysis in the solid state.     

Syntheses,structural characteristics,and antimicrobial activities of new organotin(IV) 3-(4-bromophenyl)-2-ethylacrylates

New organotin(IV) carboxylates, [n-Bu₂SnL₂] (1), [Et₂SnL₂] (2), [Me₂SnL₂] (3), [n-Oct₂SnL₂] (4), [n-Bu₃SnL] _n (5), [Me₃SnL] _n (6), and [Ph₃SnL] _n (7), where L?=?3-(4-bromophenyl)-2-ethylacrylate, were synthesized and characterized by elemental analysis, FT-IR, and multinuclear NMR (¹H, ¹³C, and ¹¹⁹Sn). Spectroscopic studies confirm coordination of L to the organotin moiety via COO group. Single-crystal X-ray analysis reveals bridging mode of coordination in 6. Packing diagram established a supramolecular cage-like structure for 6 due to Sn–O interactions (3.287?Å). Subsequent antimicrobial activities proved them to be active biologically.     

Diorganotin(IV) complexes with furan-2-carbohydrazone derivatives: synthesis,characterization, crystal structure and antibacterial activity

Four new diorganotin(IV) complexes, R₂SnL (L?=?L^a: R?=?Me 1, Ph 2; L?=?L^b: R?=?Me 3, and Ph 4), have been synthesized by reaction of hydrazone ONO donors, 5-bromo-2-hydroxybenzaldehyde furan-2-carbohydrazone (H₂L^a) and 2-hydroxynaphthaldehyde furan-2-carbohydrazone (H₂L^b) with diorganotin(IV) dichloride in the presence of a base. The compounds have been investigated by elemental analysis and IR, ¹H NMR, and ¹¹⁹Sn NMR spectroscopies. Spectroscopic studies show that the hydrazone is a tridentate dianionic ligand, coordinating via the imine nitrogen and phenolic and enolic oxygens. The structures of H₂L^b and 3 have also been confirmed by X-ray crystallography. The results show that the structure of 3 is a distorted square pyramid with imine nitrogen in apical position. The in vitro antibacterial activities of ligands and complexes have been evaluated against gram-positive (Bacillus cereus and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria. H₂L^a and H₂L^b show no activity but the diphenyltin(IV) complexes exhibit good activities towards two bacterial strains in comparison with standard bacterial drugs.     

C,N-chelated organotin(IV) trifluoroacetates. Instability of the mono- and diorganotin(IV) derivatives.

The C,N-chelated tri-, di- and monoorganotin(IV) halides react with equimolar amounts of CF₃COOAg to give corresponding C,N-chelated organotin(IV) trifluoroacetates. The set of prepared tri-, di- and monoorganotin(IV) trifluoroacetates bearing the L^CN ligand (where L^CN is 2-(N,N-dimethylaminomethyl)phenyl-) was structurally characterized by X-ray diffraction analyses, multinuclear NMR and IR spectroscopy. In the case of triorganotin(IV) trifluoroacetates and (L^CN)₂Sn(OC(O)CF₃)₂, no tendency to form hydrolytic products, or instability towards the moisture was observed. L^CNRSn(OC(O)CF₃)₂ (where R is n-Bu or Ph) and L^CNSn(OC(O)CF₃)₃ forms upon crystallization from THF in the air mainly dinuclear complexes in which the two tin atoms are interconnected either by hydroxo-bridges or by an oxo-bridge and/or by a bridging trifluoroacetate(s). In the case of hydrolysis of L^CN(n-Bu)Sn(OC(O)CF₃)₂, a zwitterionic stannate of formula L^CN(n-Bu)Sn(OC(O)CF₃)₂·CF₃COOH was isolated from the mother liquor, too. Products of hydrolysis of L^CN(n-Bu)Sn(OC(O)CF₃)₂ and L^CNSn(OC(O)CF₃)₃, and some other oxygen bridged organotin(IV) compounds containing the same ligand, were tested as possible catalysts of some transesterification reactions as well as in direct dimethyl carbonate (DMC) synthesis from CO₂ and methanol.     

Synthesis and spectroscopic characterization of new organotin(IV) complexes with bis(3,5-dimethylpyrazol-1-yl)dithioacetate

New organotin(IV) derivatives containing the anionic ligand bis(3,5-dimethylpyrazolyl)dithioacetate [L₂CS₂]^? have been synthesized by reaction of SnR _n X_{4? n} (R?=?Me, Ph, ⁿ Bu or Cy; n?=?1–3) acceptors and Li[L₂CS₂]. Mononuclear complexes of the type [L₂CS₂]R _n SnCl_{4? n ?1}} have been obtained and fully characterized by elemental analyses and FT-IR in the solid state, and by NMR (¹H and ¹¹⁹Sn) spectroscopy, conductivity measurements and electrospray ionization mass spectrometry (ESI-MS) in solution. ESI-MS spectra of methanol solutions of diorganotin derivatives, recorded with fragmentor potentials of 0, 50, 100 and 150?V, show the occurrence at 150?V of peaks attributable to the loss of the CS₂ group from the ligands and the formation of stable tetraorganodistannoxane species.     

Structural and antimicrobial studies of potassium hydrotris(2-mercaptobenzathiazolyl)borate and its organotin(IV) derivatives

Potassium hydrotris(2-mercaptobenzathiazolyl)borate (KL) was formed by the solid state reaction of potassium borohydride and 2-mercaptobenzathiazoline. This ligand was reacted with R _n SnCl_4?n (R =?methyl, butyl and phenyl, n =?2 and 3) in dichloromethane and four different neutral organotin(IV) complexes were obtained. All compounds were characterized by elemental analyses, FT-IR and multinuclear NMR (¹H, ¹³C, ¹¹ B and ¹¹⁹Sn) spectroscopy. Spectroscopic data indicate the six-coordinated nature of tin in its di and triorganotin(IV) complexes.

To check the toxic potential of the ligand and its organotin(IV) complexes, selected bacterial (E. coli, S. epidemidis and S. dysenteriae) and fungal (A. niger, C. albicanes and A. flaves) species were screened. The results were compared with standard drugs kinamycine and miconazole for bacterial and fungal activity, respectively. The toxicity of the organotin(IV) complexes depends on the number and nature of organic groups attached to the tin atom; triorganotin(IV) complexes exhibit better inhibition than diorganotin(IV) complexes. All compounds were also screened on the cyanobacterial strains (Aulosira fertillissma, Anabaena variabilis, Anabaena species and Nostoc muscorum). Results show that the compounds inhibit the growth of organisms at very low concentration.     

Synthesis, characterisation and X-ray structures of diorganotin(IV) and iron(III) complexes of dianionic terdentate Schiff base ligands

Diorganotin(IV) complexes, [SnR₂L] (1)-(4), (R = Me, Ph), of the terdentate Schiff bases N-[(2-pyrroyl)methylidene]-N′-tosylbenzene-1,2-diamine (H₂L¹) and N-[(2-hydroxyphenyl)metylidene]-N′-tosylbenzene-1,2-diamine (H₂L²) have been synthesised. The complexes were obtained by addition of the appropriate ligand to a methanol suspension of the corresponding diorganotin(IV) dichloride in the presence of triethylamine. However, the reaction between the precursor [η⁵-C₅H₅Fe(CO)₂]₂SnCl₂ and the Schiff bases in the presence of triethylamine gave (5) and (6), respectively. The crystal structures of the ligands and complexes have been studied by X-ray diffraction. The structure of [SnR₂L] complexes shows the tin to be five-coordinate in a distorted square pyramidal environment with the dianionic ligand acting in a terdentate manner. In 5 and 6, the iron atom is in a slightly distorted octahedral environment and is meridionally coordinated by two ligands. Spectroscopic data for the ligands and complexes (IR, ¹H, ¹³C and ¹¹⁹Sn NMR and mass spectra) are discussed and related to the structural information.