Crystal structure of [Bi(<Emphasis Type="Italic">N</Emphasis>-ethylthiourea)<Subscript>4</Subscript>(ClO<Subscript>4</Subscript>)<Subscript>2</Subscript>]ClO<Subscript>4</Subscript>

The structure of the bismuth(III) complex with N-ethylthiourea (Ettu) has been determined for the first time. We found that the crystal structure of [Bi(Ettu)₄(ClO₄)₂]ClO₄ is built of distorted octahedral cations [Bi(Ettu–S)₄(ClO₄)₂]ClO₄]⁺ and anions ClO₄^-. The deviation of one of the two independent Ettu molecules from the plane structure is explained by the mutual repulsion of the ligands and the formation features of hydrogen bonds. The C₂H₅(Ettu) group is in the cis position relative to the thiocarbonyl group.     

Dinuclear complex of gold(III) with 1,3-diaminopropane (HL), [Au<Subscript>2</Subscript>(HL)(L)<Subscript>2</Subscript>](ClO<Subscript>4</Subscript>)<Subscript>3</Subscript>(OH): Synthesis and crystal and molecular structures

The dinuclear gold(III) complex, [Au₂(HL)(L)₂](ClO₄)₃(OH) (I) (HL = 1,3-diaminopropane), with two amide bridges has been synthesized for the first time. According to the X-ray diffraction data, the crystal structure of complex I consists of the complex cations [Au₂(HL)(L)₂]⁴⁺ and anions ClO₄⁻ and OH⁻. The coordination sites AuN₄ are insignificantly distorted squares. In the four-membered ring Au₂N₂, the gold atoms are bound by the bridging nitrogen atoms of the deprotonated primary amine.     

Synthesis,structure, and electrochemistry of <Emphasis Type="Italic">trans</Emphasis>-[Co<Superscript>III</Superscript>{(BA)<Subscript>2</Subscript>pn}(L)<Subscript>2</Subscript>]ClO<Subscript>4</Subscript> complexes

The structure, spectroscopic, and electrochemical properties of [Co{(BA)₂pn}(L)₂]ClO₄ complexes, where (BA)₂pn = N,N′-bis(benzoylacetone)-1,3-propylenediimine dianion and the two ancillary ligands (L) are pyridine, py (1), and 4-methylpyridine, 4-Mepy (2), have been investigated. These complexes have been characterized by elemental analyses, IR, UV–Vis and ¹H-NMR spectroscopy. The crystal structure of [Co{(BA)₂pn}(py)₂]ClO₄ (1) has been determined by X-ray diffraction. The coordination geometry around cobalt(III) is best described as a distorted octahedron. The electrochemical reduction of these complexes at a glassy carbon electrode in acetonitrile solution indicates that the first reduction process corresponding to Co^III–Co^II is electrochemically irreversible, which is accompanied by the dissociation of the axial N(py)–cobalt bonds. This process becomes quasi-reversible upon the addition of excess py ligands. The second reduction step of Co^II/I shows reversible behavior and is not influenced by the nature of the axial ligands. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Standard molar enthalpies of formation of [RE(Gly)<Subscript>4</Subscript>(Im)(H<Subscript>2</Subscript>O)](ClO<Subscript>4</Subscript>)<Subscript>3</Subscript> (<Emphasis Type="Italic">RE</Emphasis>=Eu,Sm)

The two complexes, [RE(Gly)₄(Im)(H₂O)](ClO₄)₃(s)(RE = Eu, Sm), have been synthesized and characterized. The standard molar enthalpies of reaction for the following reactions, RECl₃·6H₂O(s)+4Gly(s)+Im(s)+3NaClO₄(s) = =[RE(Gly)₄(Im)(H₂O)](ClO₄)₃(s)+3NaCl(s)+5H₂O(l), were determined by solution-reaction colorimetry. The standard molar enthalpies of formation of the two complexes at T = 298.15 K were derived as Δ_f H _m^Θ {Eu(Gly)₄(Im)(H₂O)}(ClO₄)₃(s)} = = −(3396.6±2.3) kJ mol⁻¹ and Δ_f H _m^Θ {Sm(Gly)₄(Im)(H₂O)}(ClO₄)₃(s)} = −(3472.7±2.3) kJ mol⁻¹, respectively.     

(Tetramethylcyclobutadiene)cobalt complexes 7. Mono- and dinuclear arene complexes containing the [(C<Subscript>4</Subscript>Me<Subscript>4</Subscript>)Co]<Superscript>+</Superscript> fragment

The mononuclear arene complexes [Cb*Co(arene)]⁺ (3a–g; Cb* = C₄Me₄; arene is biphenyl (a), diphenylmethane (b), 1,2-diphenylethane (c), diphenyl ether (d), p-terphenyl (e), 1,2-dimesitylethane (f), or 1,3-dimesitylpropane (g)) were synthesized by the reactions of arenes either with the benzene complex [Cb*Co(C₆H₆)]⁺ (1) under visible light irradiation or with the acetonitrile derivative [Cb*Co(MeCN)₃]⁺ (2) in refluxing THF. The reactions of 2 with 1,2-diphenyle-thane, 1,3-dimesitylpropane, and p-terphenyl in a ratio of 2: 1 afforded the dinuclear complexes [Cb*Co(μ-η:η-arene)CoCb*]²⁺ (4c,e,g). The stability of the dinuclear arene complexes was estimated by DFT calculations. The structures of the complexes [3a]PF₆ and [3e]PF₆ ere established by X-ray diffraction. For Part 6, see Ref. 1. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 535–539, March, 2008.     

Crystal structures of [Hg(<Emphasis Type="Italic">N</Emphasis>-ethylthiourea)<Subscript>2</Subscript>(CN)<Subscript>2</Subscript>] and [Hg(<Emphasis Type="Italic">N</Emphasis>-propylthiourea)<Subscript>2</Subscript>(CN)<Subscript>2</Subscript>]

Two mercury(II) cyanide complexes of N-ethylthiourea (Ettu) and N-propylthiourea (Prtu) ligands, [Hg(Ettu)₂(CN)₂] (1) and [Hg(Prtu)₂(CN)₂] (2), were prepared and their crystal structures were determined by X-ray crystallography. In both structures, the mercury atom is coordinated to two sulfur atoms of thioureas and two cyanide carbon atoms in a pseudo-tetrahedral mode with the bond angles in the range of 90.52(11)–162.2(3)°. The structures are stabilized by N-H—S, N-H—N, and C-H—N intramolecular and intermolecular hydrogen bonds.     

Reaction of Sulfur and Oxygen-Bridged 8-Quinolinolato Trinuclear Molybdenum Cluster [Mo<Subscript>3</Subscript>OS<Subscript>3</Subscript>(qn)<Subscript>3</Subscript>(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>]<Superscript>+</Superscript> with Acetylene Carboxylic Acids

The reaction of a sulfur and oxygen-bridged 8-quinolinolato trinuclear molybdenum cluster [Mo₃OS₃(qn)₃(H₂O)₃]⁺ (3; Hqn = 8-quinolinol) with equimolar amounts of acetylene carboxylic acid, 4-pentynoic acid, 5-hexynoic acid, acetic acid, and pimelic acid gave clusters having μ-carboxylato groups, [Mo₃OS₃(qn)₃(H₂O)(μ-HC≡CCOO)] (6), [Mo₃OS₃(qn)₃(H₂O)(μ-HC≡C(CH₂)₂COO)] (7), [Mo₃OS₃(qn)₃(H₂O)(μ-HC≡C(CH₂)₃COO)] (8), [Mo₃OS₃(qn)₃(H₂O)(μ-CH₃COO)] (4), and [{Mo₃OS₃(qn)₃(C₂H₅OH)}₂(μ-C₇H₁₀O₄)] (5), respectively. X-ray structural analyses, ¹H NMR, and electronic spectra of these clusters made clear that each of the COO⁻ groups of the reagents bridges two Mo atoms in each cluster and that no adduct formation occurred at the sulfurs in the clusters. The reaction of 3 with a large excess-molar amount (50 times) of acetylene carboxylic acid gave [Mo₃OS(μ₃-SCH=C(COOH)S)(qn)₃(H₂O)(μ-HC≡CCOO)] (9) with two molecules of acetylene carboxylic acid, one acting as a carboxylato bridge and the other in adduct formation, as supported by the electronic and ¹H NMR spectra. The corresponding aqua cluster [Mo₃OS₃(H₂O)₉]⁴⁺ (1), on the contrary, reacts with acetylene carboxylic acid to give adduct [Mo₃OS(μ₃-SCH=C(COOH)S)(H₂O)₉]⁴⁺ (2). Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Functionalization of one or two methyl groups in the [Cp*<Subscript>2</Subscript>RuBr]<Superscript>+</Superscript>Br<Superscript>−</Superscript> complex in the reaction with bromine

The reaction of [Cp*₂RuBr]⁺Br⁻ with bromine in CH₂Cl₂ (CD₂Cl₂) in an inert atmosphere at room temperature produces the complexes [Cp*Ru(Br)C₅Me₄CH₂Br]⁺Br₃ ⁻ (syn conformer), [Cp*Ru(Br)C₅Me₃(CH₂Br)₂]⁺ (syn and anti conformers), and [Ru(Br)(C₅Me₄CH₂Br)₂]⁺ (syn conformer). All complexes were characterized by ¹H and ¹³C NMR spectroscopy; the former complex, by elemental analysis. These complexes were also prepared by the reaction of [Cp*RuC₅Me₄CH₂]⁺BF₄ ⁻ with bromine in CH₂Cl₂. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2712–2718, December, 2005.     

Photochromic single-molecule magnets based on oxocarboxylate Mn<Subscript>12</Subscript> clusters and mononitrosyl Ru complexes

Mono- and dianionic oxocarboxylate Ru-Mn₁₂ clusters, [RuNO(en)₂Cl]-[Mn₁₂O₁₂(O₂CR)₁₆(H₂O)₄]₂ (R = Ph (1)), [RuNO(en)₂Cl][Mn₁₂O₁₂(O₂CR)₁₆(H₂O)₄] (R = C₆F₅ (2), CH₂Cl (3), R = CHCl₂ (4)), and [RuNO(NH₃)₄OH][Mn₁₂O₁₂(O₂CR)₁₆(H₂O)₄] (R = CH₂Cl (5), CHCl₂ (6)) containing photochromic mononitrosyl ruthenium complexes as cations were synthesized. The magnetic properties of the complexes in static and alternating magnetic fields were studied, and compounds 1–6 were found to be molecular nanomagnets. By IR spectroscopy, they were shown to exhibit also photochromic properties.     

Reactivity of triangular oxalate cluster complexes [M<Subscript>3</Subscript>Q<Subscript>7</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>)<Subscript>3</Subscript>]<Superscript>2−</Superscript> (M = Mo or W; Q = S or Se)

The reactions of the oxalate complexes [M₃Q₇(C₂O₄)₃]²⁻ (M = Mo or W; Q = S or Se) with Mn^II, Co^II, Ni^II, and Cu^II aqua and ethylenediamine complexes in aqueous and aqueous ethanolic solutions were studied. The previously unknown heterometallic complexes [Mo₃Se₇(C₂O₄)₃Ni(H₂O)₅]·3.5H₂O (1) and K₃{[Cu(en)₂H₂O]([Mo₃S₇(ox)₃]₂Br)}·5.5H₂O (2) were synthesized. In these complexes, the oxalate clusters serve as monodentate ligands. The K(H₂en)₂[W₃S₇(C₂O₄)₃]₂Br·4H₂O salt (3) was isolated from solutions containing Co^II, Ni^II, or Cu^II aqua complexes and ethylenediamine. The reaction of [Mo₃Se₇(C₂O₄)₃]²⁻ with HBr produced the bromide complex [Mo₃Se₇Br₆]²⁻, which was isolated as (Bu₄N)₂[Mo₃Se₇Br₆] (4). Complexes 1–3 were characterized by X-ray diffraction, IR spectra, and elemental analysis. The formation of 4 was detected by electrospray mass spectrometry. Dedicated to Academician G. A. Abakumov on the occasion of his 70th birthday. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1645–1649, September, 2007.     

Iron(II) and Nickel(II) Complexes of N‐Alkylimidazoles and 1‐Methyl‐1H‐1, 2, 4‐Triazole: X‐ray Studies,Magnetic Characterization,and DFT Calculations

Using the ligands N‐methylimidazole ( MeIm ), N‐ethylimidazole ( EtIm ), N‐propylimidazole ( PrIm ), and 1‐methyl‐1H‐1, 2, 4‐triazole ( MeTz ) three series with a total of 13 iron(II) complexes were isolated. The series comprise of the following complexes: (a) [Fe( MeIm )₆](ClO₄)₂ ( 1 ), [Fe( EtIm )₆](ClO₄)₂ ( 2 ), [Fe( PrIm )₆](ClO₄)₂( 3 ), [Fe( MeTz )₆](ClO₄)₂ ( 4 ), [Fe( MeIm )₆](MeSO₃)₂ ( 5 ), [Fe( EtIm )₆](MeSO₃)₂ ( 6 ), and [Fe( MeTz )₆](BF₄)₂ ( 10 ); (b) [Fe( MeIm )₄(MeSO₃)₂]( 7 ), [Fe( EtIm )₄(MeSO₃)₂] ( 8 ), and [Fe( PrIm )₄(MeSO₃)₂] ( 9 ); (c) [Fe( MeIm )₄(NCS)₂] ( 15 ), [Fe( EtIm )₄(NCS)₂] ( 16 ), and [Fe( MeTz )₄(NCS)₂] ( 17 ). Single crystal X‐ray diffraction studies were performed on 7 – 10 and 15 – 17 . Temperature dependent magnetic susceptibility measurements were performed on selective examples of all series, and confirmed them to be in the HS state over the range 6–300 K. DFT calculations were performed at BP86/def‐SV(P) and TPSSh/def2‐TZVPP level on all [Fe L ₆]²⁺ complex cations and the neutral complexes 7 – 9 and 15 – 17 . Additionally the four homoleptic nickel(II) complexes [Ni L ₆](ClO₄)₂ ( 11 : L = MeIm ; 12 : L = EtIm ; 13 : L = PrIm ; 14 : L = MeTz ) were synthesized and compounds 11 – 13 structurally characterized. UV/Vis/NIR spectroscopic measurements were carried out on all homoleptic iron(II) and nickel(II) complexes. The 10Dq values were determined to be in the range of 11547–11574 and 10471–10834 cm^–1 for the iron(II) and nickel(II) complexes, respectively.     

Density Functional Theory and Low-Temperature Matrix Investigations of CO-Loss Photochemistry from [(C<Subscript>5</Subscript>R<Subscript>5</Subscript>)Ru(CO)<Subscript>2</Subscript>]<Subscript>2</Subscript> (R = H,Me) Complexes

The photochemical CO-loss products of the diruthenium complexes [CpRu(CO) ₂]₂ (5; Cp = ⁵-C₅H₅), [Cp*Ru(CO)₂]₂ (5*; Cp* = ⁵-C₅(CH₃)₅) and CpCp*[Ru(CO)₂]₂ (5) have been studied experimentally in low-temperature (96 K) matrices in 3-methylpentane by using IR spectroscopy. It is proposed that all three complexes undergo single-CO-loss chemistry but that the products have different structures. The single-CO-loss product from 5 is proposed to have one bridging and two terminal carbonyl ligands, whereas 5* and 5 generate triply bridged CO-loss products similar to that observed from [CpFe(CO)₂]₂ and [Cp*Fe(CO)₂]₂. Double-CO-loss from 5* and 5* 9 is also apparently observed. Relativistic DFT calculations have been carried out on various isomers of the starting materials and on potential CO-loss products from 5. The calculations suggest that the triply bridged product Cp₂Ru₂(-CO)₃ (6) might have a singlet ground state in contrast to the corresponding diiron complex Cp₂Fe₂(-CO)₃ (3), which has a triplet ground state.     

Synthesis and speciation of zirconium tetrafluoride complexes with phosphoryl-containing bases Ph<Subscript>3</Subscript>PO,Bu<Subscript>3</Subscript>PO and (Me<Subscript>2</Subscript>N)<Subscript>3</Subscript>PO in solutions

Zirconium fluoro complexes with phosphoryl-containing bases (L) have been synthesized by the reaction of a suspension of ZrF₄(dmso)₂ in toluene with an excess of Ph₃PO or Bu₃PO, as well as (Me₂N)₃PO in CH₂Cl₂. The composition and structure of the complexes in CH₂Cl₂ solutions have been studied by ¹⁹F NMR in the temperature range 293–203 K. Phosphine oxides are substituted for dmso to form mainly cis-tetrafluoro species, insignificant amounts of trans-tetrafluoro species, and mer- and fac-[ZrF₃L₃]⁺ complexes. In addition to these species, the reaction with Bu3PO yields the dimeric oxo complex (µ-O)[ZrF₃(Bu₃PO)₂]₂. Hydrolysis of fluoro complexes in CH₂Cl₂ with the use of an NBu₄OH solution in iso-PrOH does not lead to oxo and hydroxo complexes: first, the [ZrF₅L]^– complex is formed, and the final hydrolysis product is ZrF₆^2-. The fine structure of ¹⁹F NMR resonance lines for the zirconium fluoride compounds [ZrF5L]^–, cis- [ZrF₄L₂], dimeric oxo complex, and mer-[ZrF₃L₃]⁺ in organic solvents has been observed for the first time, which makes it possible to reliably identify the composition and structure of the zirconium coordination polyhedron in the complexes under consideration.     

Formation of Cu<Superscript>I</Superscript>(CH<Subscript>3</Subscript>CN)<Subscript>4</Subscript>ClO<Subscript>4</Subscript> in the reactions of copper(II) perchlorate with acetonitrile in the presence of sulfur-containing organic compounds

Cu(ClO₄)₂·6H₂O was shown to react with 2,2′-[propane-1,3-diylbis(thio-2-phenylnemethylidene]-bis(3-pyridylamine) (I) or (5Z)-2-ethoxycarbonylmethyl-(2-pyridylmethylidene)-3,5-dihydro-4H-imidazol-4-one (II) in the presence of CH₃CN with the reduction of copper(II) to copper(I) and the formation of the tetrahedral complex Cu^I(CH₃CN)₄ClO₄ (III). In the course of the reaction the organic ligands I and II were oxidized to the corresponding sulfoxides.     

Mononuclear manganese(II) and manganese(III) complexes of N<Subscript>2</Subscript>O donors involving amine and phenolate ligands: absorption spectra,electrochemistry and crystal structure of [Mn(L<Subscript>3</Subscript>)<Subscript>2</Subscript>](ClO<Subscript>4</Subscript>)

A number of mononuclear manganese(II) and manganese(III) complexes have been synthesized from tridentate N₂O aminophenol ligands (HL₁–HL₅) formed by reduction of corresponding Schiff bases with NaBH₄. Three types of tridentate N₂O aminophenols have been prepared by reducing with NaBH₄which are (a) Schiff bases obtained by bromo salicylaldehyde reaction with N,N-dimethyl/N,N-diethyl ethylene diamine (HL₁, HL₂), (b) Schiff bases obtained by condensing salicylaldehyde/bromo salicylaldehyde and picolyl amine (HL₃, HL₄), (c) pyridine-2-aldehyde and 2-aminophenol (HL₅). All the manganese complexes have been prepared by direct addition of manganese perchlorate to the corresponding ligands and were characterized by the combination of i.r., u.v.–vis spectroscopy, magnetic moments and electrochemical studies. The u.v.–vis spectra of all of the manganese(III) complexes show two weak d–d transitions in the 630–520 nm region, which support a distorted octahedral geometry. The electron transfer properties of all of the manganese(III) complexes (1–4 and 6) exhibit mostly similar characteristics consisting two redox couples corresponding to the Mn^III → Mn^II reductions and Mn^III → Mn^IV oxidations. The electronic effect on the potential has also been studied by changing different substituents in the ligands. In all cases, an electron-donating group stabilizes the higher oxidation state and electron withdrawing group prefers the lower oxidation state. The cyclic voltammogram of [Mn^II(L₅)₂] shows an irreversible oxidation Mn^II → Mn^III at −0.88 V, followed by another quasi-reversible oxidation Mn^III → Mn^IV at +0.48 V. The manganese(III) complex (3) [Mn(L₃)₂]ClO₄has been characterized by X-ray crystallography.     

Multifunctional iron thiocarboxylate complexes: synthesis,reactivity and structure of CpFe(CO)<Subscript>2</Subscript>SCO-3,5-C<Subscript>6</Subscript>H<Subscript>4</Subscript>(COCl)<Subscript>2</Subscript>

A controlled substitution reaction of the chlorine atoms of 1,3,5-benzenetricarbonyl trichloride by the organoiron fragment (CpFe(CO)₂S) has been achieved. The complexes CpFe(CO)₂SCO-3,5-C₆H₃(COCl)₂ (1), 1,3-[CpFe(CO)₂SCO]₂-5-C₆H₃COCl (2) and 1,3,5-[CpFe(CO)₂SCO]₃C₆H₃ (3) were prepared from the reaction of (μ-S _x )[CpFe(CO)₂]₂ (x = 3, 4) with 1,3,5-C₆H₃(COCl)₃ in a 1:1, 2:1, or 3:1 metal to ligand molar ratio. The reactions of (1) with amines, thiols, and carboxylic acids produce the trifunctional mono-iron complexes CpFe(CO)₂SCO-3,5-C₆H₃(COY)₂ [Y = NR₂ (4), SR (5), OCOR (4)]. The X-ray structure determination of (1) is reported.     

Hydrothermal synthesis and crystal structure of [Ni(Bptc)<Subscript>2</Subscript>(Bimb)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>]

In the compound [Ni(Bptc)₂(Bimb)₂(H₂O)₂] (I), where H₄Bptc is 3,3′,4,4′-biphenyltetracarboxylic acid; Bimb is 4,4′-bis(1-imidazolyl)biphenyl), Ni(II) has a distorted octahedral coordination geometry, which was bonded with two N atoms from two Bimb ligands, two O atoms from two H₂Bptc²⁻ ligands and two water O atoms. The crystal structure of compound I is stabilized by the π-π-stacking and hydrogen bonds interaction.     

Synthesis and structure of [UO<Subscript>2</Subscript>(C<Subscript>2</Subscript>O<Subscript>4</Subscript>){CONH<Subscript>2</Subscript>N(CH<Subscript>3</Subscript>)<Subscript>2</Subscript>}<Subscript>2</Subscript>]

The single crystals of [UO₂(C₂O₄){CONH₂N(CH₃)₂}₂] were synthesized and studied by X-ray diffraction. The crystals are monoclinic, a = 7.461(2) Å, b = 8.828(2) Å, c = 11.756(2) Å, β = 107.21(3)°, space group Pc, Z = 2, R = 2.94%. The structure comprises infinite chains [UO₂(C₂O₄){CONH₂N(CH₃)₂}₂] extended along [001] and corresponding to the AT¹¹M ₂ ¹ crystallochemical group (A = UO ₂ ²⁺ , T¹¹ = C₂O ₄ ^2? , M¹ = N,N-CONH₂N(CH₃)₂) of uranyl complexes. The chains are connected into a three-dimensional framework by hydrogen bonds involving the oxygen atoms of oxalate and uranyl ions and the N,N-dimethylcarbamide methyl groups.     

Thermal study of cyclopalladated complexes of the type [Pd<Subscript>2</Subscript>(dmba)<Subscript>2</Subscript>X<Subscript>2</Subscript>(bpe)]

The synthesis, characterization and thermal analysis of the novel cyclometallated compounds [Pd₂(dmba)₂Cl₂(μ-bpe)] (1), [Pd₂(dmba)₂(N₃)₂(μ-bpe)] (2), [Pd₂(dmba)₂(NCO)₂(μ-bpe)] (3), [Pd₂(dmba)₂(SCN)₂(μ-bpe)] (4), [Pd₂(dmba)₂(NO₃)₂(μ-bpe)] (5) (bpe=trans-1,2-bis(4-pyridyl)ethylene; dmba=N,N-dimethylbenzylamine) are described. The thermal stability of [Pd₂(dmba)₂X₂(μ-bpe)] complexes varies in the sequence 1>4>3>2>5. The final residues of the thermal decompositions were characterized as metallic palladium by X-ray powder diffraction.     

Iron(II) complexes [Fe(DfgH)<Subscript>2</Subscript>(3-CONH<Subscript>2</Subscript>-Py)<Subscript>2</Subscript>] and [Fe(DfgH)<Subscript>2</Subscript>(4-COOC<Subscript>2</Subscript>H<Subscript>5</Subscript>-Py)<Subscript>2</Subscript>]: Synthesis and structures

The complexes [Fe(DfgH)₂(3-CONH₂-Py)₂] (I) and [Fe(DfgH)₂(4-COOC₂H₅-Py)₂] (II), where DfgH₂ is α-benzyl dioxime, were obtained and examined by X-ray diffraction analysis. The equatorial planes of the coordination octahedra of the metal ions consist of two monodeprotonated α-benzyl dioxime residues united through intramolecular hydrogen bonds O-H…O into a pseudomacrocyclic system. The neutral molecules 3-CONH₂-Py and 4-COOC₂H₅-Py are coordinated to the Fe²⁺ ion through the N atom of the heterocycle. Structure I is layered and structure II is molecular. Intermolecular interactions N-H…O are responsible for the formation of layers in crystal structure I.