Manganese(III) and rhenium(II) complexes with bulky 4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-iminobenzoquinonato ligands via carbonyls of corresponding metals

Four-coordinate complex Mn^III(ISQ-Prⁱ)(AP-Prⁱ) (1), where ISQ-Prⁱ = 4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-iminobenzosemiquinonate anion-radical, AP-Prⁱ = 4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-amidophenolate dianion, has been prepared by the reaction of Mn₂(CO)₁₀ with free 4,6-di-tert-butyl-N-(2,6-di-iso-propylphenyl)-o-iminobenzoquinone (IBQ-Prⁱ) in the molar ratio 1:4 in toluene. In contrast to manganese, rhenium carbonyl reacts with o-iminobenzoquinone to form complex Re^II(ISQ-Prⁱ)₂(CO)₂ (2) with the retention of two carbonyls in coordination sphere of rhenium. The complexes have been characterized by IR, UV-Vis, and EPR spectroscopies. Molecular structures of compounds 1 and 2 have been determined by single-crystal X-ray crystallography. Compound 1 is centro-symmetric square-planar molecule with delocalized mixed valent state of AP-Prⁱ and ISQ-Prⁱ ligands. EPR spectrum of 1 in solid at 300-77 K is typical for manganese complexes with S = 3/2 state. The effective magnetic moment of 1 is 1.96 μ_B at temperature 5 K as it was established by variable-temperature magnetic susceptibility measurements. Six-coordinate octahedral complex 2 possesses an S = 1/2 ground state, which is attained via strong intramolecular antiferromagnetic interaction between t_2g orbital unpaired electron of the low spin Re^II ion and the unpaired electron on π-orbital of the radical ligand.     

Dechlorination of diphenyl chlorophosphate with tin and sodium 3,6-di-tert-butyl-ortho-semiquinones

Dechlorination reactions of diphenyl chlorophosphate (PhO)₂P(O)Cl with 3,6-di-tert-butyl-ortho-semiquinone complexes of triphenyl tin, SQSn(Ph)₃ and sodium, SQNa have been investigated by electron spin resonance (ESR) both in solutions at 300 K and in solid phase at 77 K using mechanochemical activation. Paramagnetic 3,6-di-tert-butyl-ortho-semiquinone ligand (SQ) was used as spin probe to monitor changes in the Sn coordination sphere during the dechlorination reaction of (PhO)₂P(O)Cl and consecutive formation of tin chloride derivatives SQSnCl(Ph)₂, SQSnCl₂Ph, and SQSnCl₃. Their structure was revealed based on the analysis of hyperfine interaction constants due to ¹H nuclei in the 4,5-positions of the aromatic ring of the SQ ligand, hyperfine interaction constants due to ³⁵Cl and ³⁷Cl nuclei of chlorine atoms in the Sn coordination sphere, and hyperfine interaction constants due to ¹¹⁷Sn and ¹¹⁹Sn nuclei of the central metal ion. Interaction of SQSnCl₃ with (PhO)₂P(O)Cl leads to the formation of a meta-stable radical-anion complex [SQSnCl₄]⁻ P⁺(O)(OPh)₂, which transforms to SQSnCl₃?P(O)R₃, a stable adduct of SQSnCl₃ with dechlorinated phosphate of a general formula P(O)R₃. Analysis of solution dechlorination reaction products suggests the formation of diphenyl-phosphoryl radical (PhO)₂P(O), which was not observed in solutions. Dechlorination of (PhO)₂P(O)Cl with sodium 3,6-di-tert-butyl-ortho-semiquinone SQNa can proceed in solid phase in liquid nitrogen at 77 K via mechanochemical activation using a ball mill. ESR analysis of the cryo-mechanochemical reaction showed the formation of the adduct of (PhO)₂P(O) radical with 3,6-di-tert-butyl-ortho-quinone.     

Synthesis and characterization of complexes of the type [Pt(amine)4]I2 and trans-[Pt(CH3NH2)2(H3CNC(CH3)2)2]I2 by crystallography and multinuclear magnetic resonance spectroscopy

Complexes of the type [Pt(amine)₄]I₂ were synthesized and characterized mainly by multinuclear (¹⁹⁵Pt, ¹H and ¹³C) magnetic resonance spectroscopy. The compounds were prepared with different primary amines, but not with bulky amines, due to steric hindrance. In ¹⁹⁵Pt NMR, the signals were observed between −2715 and −2769 ppm in D₂O. The coupling constant ³J(¹⁹⁵Pt-¹H) for the MeNH₂ complex is 42 Hz. In ¹³C NMR, the average values of the coupling constants ²J(¹⁹⁵Pt-¹³C) and ³J(¹⁹⁵Pt-¹³C) are 18 and 30 Hz, respectively. The crystal structure of [Pt(EtNH₂)₄]I₂ was determined by X-ray diffraction methods. The Pt atom is located on an inversion center. The structure is stabilized by H-bonding between the amines and the iodide ions. The compound with n-BuNH₂ was found by crystallographic methods to be [Pt(n-BuNH₂)₄]₂I₃(n-BuNHCOO). The crystal contains two independent [Pt(CH₃NH₂)₄]²⁺ cations, three iodide ions and a carbamate ion formed from the reaction of butylamine with CO₂ from the air. When the compound [Pt(CH₃NH₂)₄]I₂ was dissolved in acetone, crystals identified as trans-[Pt(CH₃NH₂)₂(H₃CNC(CH₃)₂)₂]I₂ were isolated and characterized by crystallographic methods. Two trans bonded MeNH₂ ligands had reacted with acetone to produce the two N-bonded Schiff base Pt(II) compound.     

Quantifying the trans influence of triphenylarsine. Crystal and molecular structures of cis-[PtCl2(SMe2)(AsPh3)] and cis-[PtCl2(AsPh3)2]·CHCl3

Reaction between a mixture of cis-trans-[PtCl₂(SMe₂)₂] and 1 equiv. AsPh₃ in chloroform gives cis-[PtCl₂(SMe₂)(AsPh₃)] crystallizing in P2₁/n with a=10.397(2), b=14.876(3), c=13.956(3) Å, β=90.86(3)° and Z=4. Selected geometrical parameters are PtAs 2.3531(10), PtS 2.262(2), PtCl (trans to S) 2.301(2), PtCl (trans to As) 2.328(2) Å and SPtAs 88.85(6), SPtCl(2) 90.77(8), AsPtCl(1) 91.07(6) and ClPtCl 89.42(7)°. cis-[PtCl₂(AsPh₃)₂]·CHCl₃ crystallizes in P2₁/c with a=20.557(4), b=9.5951(19), c=20.147(4) Å, β=96.77(3)° and Z=4. Selected geometrical parameters are PtAs(1) 2.3599(9), PtAs(2) 2.3770(9), PtCl(1) (trans to As(1)) 2.3515(18), PtCl(2) (trans to As(2)) 2.3251(18) Å and AsPtAs 97.87(3), As(1)PtCl(2) 88.67(5), As(2)PtCl(1) 84.30(5) and ClPtCl 89.32(7)°. By comparison with related structures from the literature the following trans influence series was established PMe₂Ph>PPh₃>AsPh₃≈SbPh₃>Me₂SO≈SMe₂≈SPh₂>NH₃≈olefin>Cl⁻>MeCN.     

New aryl phosphinite ligands avoiding ortho-metallation: Synthesis and molecular structures of trans-[PdCl2(PPh2OR)2] and trans-[Rh(CO)Cl(PPh2OR)2] (R = 2,4,6-Me3C6H2; 2,6-Ph2C6H3)

The new aryl phosphinites PPh₂OR (R = 2,4,6-Me₃C₆H₂, 1; R = 2,6-Ph₂C₆H₃, 2) have been prepared from chlorodiphenylphosphine and the corresponding phenols. In these ligands, the ortho-positions of the aromatic phosphite function are blocked by methyl and phenyl substituents, which allows coordination to metal centres without ortho-metallation. Thus, reaction with [PdCl₂(cod)] leads to the complexes trans-[PdCl₂(PPh₂OR)₂] (R = 2,4,6-Me₃C₆H₂, 3; R = 2,6-Ph₂C₆H₃, 4), while the reaction with [Rh₂(CO)₄Cl₂] gives trans-[Rh(CO)Cl(PPh₂OR)₂] (R = 2,4,6-Me₃C₆H₂, 5; R = 2,6-Ph₂C₆H₃, 6). The single-crystal X-ray structure analyses of 3 and 5 confirm the trans-coordination of the new ligands in these square-planar complexes.     

Spectroscopic and electrochemical properties of a new nitrosyl-complex of Ru(II): trans-[Ru(NO){(CH3CH2)2PCH2CH2P(CH2CH3)2}2Cl](PF6)2

A new ruthenium nitric oxide complex with the bidentate phosphine, 1,2-bis(diethylphosphino)ethane (depe), has been synthesized and characterized by UV-Vis, infrared, EPR, NMR, electrochemical techniques and X-ray structure determination. The electronic spectrum showed a typical band of dπ→pπ* charge-transfer (CT) transition, assigned to Ru(II)NO transition, and the vibrational spectrum exhibited a peak of nitrosyl ligand at (ν_NO=1851 cm⁻¹). A model structure for this complex has been proposed based on ¹H, ¹H{³¹P}, ³¹P{¹H}, ¹³C{¹H}, COSY ¹H¹H{³¹P}, J-Resolved, HSQC, HMBC, HSQC ¹H¹³C{³¹P} and ¹H¹³C HSQC/¹H¹H TOCSY spectral data, and confirmed by X-ray diffraction. The nitrosonium character for the NO ligand become evident through both electron paramagnetic resonance and X-ray data (angle RuNO=177.4(3)°). The reversible monoeletronic process at E_1/2=0.040 V versus SHE was assigned to the ligand NO⁺/NO redox couple. Under treatment with Cd(Hg) solutions containing the [Ru(NO)(depe)₂Cl](PF₆)₂ yields a signal in the EPR spectrum (g_⊥=1.99 and g_//=1.88) which fitted quite well with the simulated spectra of coordinated NO species.     

Geometrical isomers of bis(benzimidazol-2-ylethyl)sulfide)cobalt(II) diperchlorates: synthesis, structure, spectra and redox behavior of pink-[Co(bbes)2](ClO4)2 and blue-[Co(bbes)2](ClO4)2

1:1 and 1:2 cobalt complexes of bis(benzimidazol-2-ylmethyl)amine (bbma) bis(benzimidazol-2-ylmethyl)sulfide (bbms), bis(benzimidazol-2-ylethyl)sulfide (bbes) and diethylenetriamine (dien) were prepared and their spectral and redox behavior studied. Two geometrical isomers pink-[Co(bbes)₂]²⁺ and blue-[Co(bbes)₂]²⁺ were obtained when the complexes were prepared by using with bbes and they were separated manually and recrystallized. The octahedral structure of pink-[Co(bbes)₂]²⁺ was resolved by X-ray analysis. The electronic spectra show the presence of two geometrical isomers for Co(bbes)₂²⁺ in the solid state; for example, the spectral bands of pink-[Co(bbes)₂]²⁺ differs markedly with those of blue-[Co(bbes)₂]²⁺. This is consistent with the results obtained from magnetic measurements (5.10 BM for pink-Co(bbes)₂²⁺ and 4.72 BM for blue-[Co(bbes)₂]²⁺). Further, the behavior of the ligands (bbma, bbms, bbes) at different pH conditions was determined on the basis of ¹³C NMR studies. The redox potentials [Co(II)/Co(I)] of the complexes follow the trend [Co(bbma)₂]²⁺ < [Co(bbms)₂]²⁺ ≈ [Co(bbes)₂]²⁺ which demonstrates the stabilization of the Co(II) ion is more by both weak σ-donor and weak π-acceptor ligands rather than by σ-donor ligand.     

Solution-mediated syntheses and characterizations of two new zincophosphites [C6H14N2]0.5[Zn(H2PO3)2] and [C4H12N2]0.5[(CH3)2NH2][Zn2(HPO3)3]

Two new zincophosphites [C₆H₁₄N₂]_0.5[Zn(H₂PO₃)₂] 1 and [C₄H₁₂N₂]_0.5[(CH₃)₂NH₂][Zn₂(HPO₃)₃] 2 have been solvothermally synthesized in mixed solvents of N,N-dimethylformamide (DMF) and 1,4-dioxane (DOA), respectively. Single-crystal X-ray diffraction analysis reveals that compound 1 exhibits a neutral inorganic chain formed by ZnO₄ and HPO₂(OH) units. Interestingly, the left- and right-handed hydrogen-bonded helical chains are alternately formed via the hydrogen-bonds between two adjacent chains. Compound 2 exhibits a layer structure with 4- and 12-MRs formed by ZnO₄ and HPO₃ units, in which two kinds of organic amine molecules both act as countercations to compensate the overall negative electrostatic charge of the anionic network.     

Spectroscopic, magnetic, and electrochemical studies of a dimeric N-substituted-sulfanilamide copper(II) complex. X-ray and molecular structure of the Cu2(N-(pyridin-2-yl)biphenyl-4-sulfonamidate)4 complex

A dinuclear copper(II) complex with a N-substituted sulfonamide as ligand has been investigated. The new N-(pyridin-2-yl)biphenyl-4-sulfonamide ligand has been prepared and structurally characterized. The copper(II) complex has been synthesized and its crystal structure, magnetic properties and EPR spectra were studied in detail. The metal centers are bridged by four nonlinear triatomic NCN groups. The coordination geometry of the copper(II) ions in the dinuclear entity is distorted square planar with two N-pyridyl and two N-sulfonamido atoms. Magnetic susceptibility data show a moderate antiferromagnetic coupling, with −2 J = 284 cm⁻¹. The EPR spectrum of the polycrystalline sample of the title compound has been measured at the X-band frequency at different temperatures.     

A new arylimido derivative of polyoxometalate (Bu4N)2[Mo6O17(NAr)2] [Ar = 2,6-(CH3)2C6H3]: Synthesis, structure and physicochemical properties

A novel bifunctionalized arylimido derivative of hexamolybdate, (Bu₄N)₂[Mo₆O₁₇(NAr)₂] [Ar = 2,6-(CH₃)₂C₆H₃] (1), in which the two 2,6-dimethylaniline groups are bounded to hexamolybdate at the cis positions, was synthesized by a facile reaction of α-octamolybdate with 2,6-dimethylaniline using DCC as a dehydration agent. The existence of strong non-typical C-H?O hydrogen bonds plays an important role in crystal structure stabilization of compound 1. The results of fluorescence spectra show that the formation of a covalent bond between 2,6-dimethylaniline molecule and hexamolybdate could efficiently quench the fluorescence intensity of 2,6-dimethylaniline molecule, with a fluorescence quencher efficiency of 87.7%. Thermal analysis results indicate that two substituted 2,6-(CH₃)₂C₆H₃ molecules bonding to the same cluster dissociated at different temperature, in well agreement with the different MoN bond length in compound 1. The electrochemical behavior of modified 1-CPE has been studied in detail. Compared with the conventional polyoxometalate (POM)-modified electrode, 1-CPE presents a merit of remarkable stability over 500 cycles due to the insolubility of the POM nanoparticles, which is especially important for practical applications.     

A seven-coordinate Fe compound: [Fe{O(CH2CO2)2}(H2O)2(NO3)]. Preparation, structure and magnetic properties

A seven-coordinate Fe^III complex, [Fe(oda)(H₂O)₂(NO₃)], was obtained after dissolving Fe(NO₃)₃ · 9H₂O in an aqueous solution of oxydiacetic acid (H₂oda) at room temperature. In the solid state, the Fe^III center adopts a pentagonal bipyramid geometry with an {FeO₇} core formed by a tridentate oda²⁻ and a bidentate in the equatorial plane, and two axial water molecules. Magnetic measurements and EPR spectra revealed the presence of S = 5/2 Fe^III centers with rhombic zero field splitting parameters (D = 0.81 cm⁻¹, E/D = 0.33 ). Weak antiferromagnetic interactions with J ≈ −0.06 cm⁻¹ operating between neighboring Fe ions connected through Fe-O-C-O?H-O-Fe paths are estimated using the molecular field approximation.     

Sn-S and Ru-Ru bonds cleavage reactions between [Ph3SnS(CH2)3SSnPh3] and Ru3(CO)12: X-ray crystal structures of [Ph3SnS(CH2)3SSnPh3] and trans-[Ru(CO)4(SnPh3)2]

The organotin complex [Ph₃SnS(CH₂)₃SSnPh₃] (1) was synthesized by PdCl₂ catalyzed reaction between Ph₃SnCl and disodium-1,3-propanedithiolate which in turn was prepared from 1,2-propanedithiol and sodium in refluxing THF. Reaction of 1 with Ru₃(CO)₁₂ in refluxing THF affords the mononuclear complex trans-[Ru(CO)₄(SnPh₃)₂] (2) and the dinuclear complex [Ru₂(CO)₆(μ-κ²-SCH₂CH₂CH₂S)] (3) in 20 and 11% yields, respectively, formed by cleavage of Sn-S bond of the ligand and Ru-Ru bonds of the cluster. Treatment of pymSSnPPh₃ (pymS = pyrimidine-2-thiolate) with Ru₃(CO)₁₂ at 55-60 °C also gives 2 in 38% yield. Both 1 and 2 have been characterized by a combination of spectroscopic data and single crystal X-ray diffraction analysis.     

Rb2[B12(OH)12]·2H2O and Rb2[B12(OH)12]·2H2O2: Hydrate and perhydrolate of rubidium dodecahydroxo-closo-dodecaborate

The orthorhombically crystallizing salts Rb₂[B₁₂(OH)₁₂]·2H₂O (a = 1576.81(9), b = 813.08(5), c = 1245.32(7) pm) and Rb₂[B₁₂(OH)₁₂]·2H₂O₂ (a = 1616.54(9), b = 814.29(5), c = 1260.12(7) pm) could be prepared from Rb₂[B₁₂H₁₂] and hydrogen peroxide. Both crystal structures were determined by X-ray single crystal diffraction and refined in the space group Cmce. They are not isostructural to the other compounds containing icosahedral dodecahydroxo-closo-dodecaborate dianions [B₁₂(OH)₁₂]²⁻ and potassium, rubidium or cesium cations already known to literature, but both title compounds crystallize quasi-isotypically exhibiting Rb⁺ cations in 10-fold oxygen coordination. The hydrogen peroxide adduct (Rb₂[B₁₂(OH)₁₂]·2H₂O₂) is explosive on shock and heat, while the hydrate (Rb₂[B₁₂(OH)₁₂]·2H₂O) is not.     

Synthesis, structures and ligating properties of 2,6-bis(phosphino)thiophenol derivatives

New t-butyl-aryl thioethers where the aryl group is 2,6-bis(phosphino)phenyl have been synthesized. The syntheses were completed via sequential ortho-lithiations of t-butylphenylsulfide, followed by chlorophosphine (ClPR₂) quenches; symmetric (2,6-bis(diphenylphosphino)phenyl, (4a)) and unsymmetric (2-diisopropylphosphino-6-diphenylphosphino)phenyl, (4b) aryl groups were obtained. Treatment of 4a with Li or Na naphthalenide yielded 2,6-bis(diphenylphosphino)thiophenol 5. Reactions of 4a or 5 with NiCl₂ · 6H₂O yielded nickel bis(phosphinothiophenolate) 6. Compounds 4a,b, 5 and 6 were characterized by ¹H and ³¹P NMR, and by mass-spectrometry. In addition, 4a, 5 and 6 were characterized by single crystal X-ray diffraction methods.     

Genetic Analysis and Physical Mapping of Lk-4(t), a Major Gene Controlling Grain Length in Rice, with a BC2F2 Population

Grain size and shape are important factors affecting grain quality and yield in rice. Mapping, tagging and identification of their related genes can lead us to understand their expression pattern and mechanism network, which is to their control. In this study we mapped a grain length controlling gene named Lk-4(t) with SSR and CAPs markers by screening 800 recessive plants in a BC₂F₂ population derived from a cross of Shuhui527xXiaoli and backcrossed with Xiaoli as the donor parent. The distribution of grain shape parameters and thousand grain weight in F₂ and BC₂F₂ population showed that backcross can diminish most unnecessary variations to identify the target gene more clearly. There were only two grain length phenotypes found among the 3 209 BC₂F₂ plants, long and short, indicating it is a qualitative trait. The frequency distribution for the grain length showed a typical segregation ratio of 3 : 1, suggesting that only one allele was responsible for the variation. By screening the recessive long grain plants with three CAPs markers, P1-EcoR V, P2-Sac I and P3-Mbo I, we tagged the locus on the arm of chromosome 3 near the centromere. Lk-4(t) was located between P1-EcoRV and P2-Sac I, with genetic distance of 0.90 cM and 0.50 cM from the two markers respectively. Mapping of the gene is a foundation for its final identification and function analysis.     

Reaction of R(Ph)SnCl2(R=Me, Et) with 2,6-diacetylpyridine bis(thiosemicarbazone) (H2DAPTSC): the crystal structures of [Me(Ph)Sn(HDAPTSC)]Cl · 1.25 MeOH and [Et(Ph)Sn(H2DAPTSC)]Cl2 · MeOH · H2O

The reactions of Me(Ph)SnCl₂ and Et(Ph)SnCl₂ with 2,6-diacetylpyridine bis(thiosemicarbazone) (H₂DAPTSC) afforded the complexes [Me(Ph)Sn(HDAPTSC)]Cl · 1.25MeOH (1) and [Et(Ph)Sn(H₂DAPTSC)]Cl₂ · MeOH · H₂O (2), respectively. Single-crystal X-ray crystallography showed that in both complexes the ligand, monodeprotonated in 1 and neutral in 2, is S(1),S(2),N(3),N(4),N(5)-coordinated, and the coordination geometry around the metal can be described as a distorted pentagonal bipyramid with the aryl and alkyl groups in axial positions. ¹H and ¹¹⁹Sn NMR studies of solution in DMSO suggest that 2 dissociates completely in this solvent, while 1 evolves to the new complex [Me(Ph)Sn(DAPTSC)], with release of H₂DAPTSC and Me(Ph)SnCl₂. These conclusions were also supported by conductivity measurements.     

Insertion reactions of CO2, OCS, and CS2 into the Sn-N bonds of (Me2N)2Sn: NMR and X-ray structural characterization of the products

The interactions of the heteroallenes CO₂, OCS, and CS₂ with (Me₂N)₂Sn have been investigated. These CX₂ species insert into the Sn-N bonds under mild conditions to provide products bis-(N,N-dimethylcarbamato)tin(II), [(Me₂NCO₂)₂Sn]₂, bis-(N,N-dimethylthiocarbamato)tin(II), [Me₂NC(O)S]₂Sn and bis-(N,N-dimethyldithiocarbamato)tin(II), (Me₂NCS₂)₂Sn. These molecules have been fully characterized by traditional spectroscopic methods as well as by X-ray crystallography. The [Me₂NC(O)S]₂Sn product is the first example of a structurally characterized Sn(II) thiocarbamate. The solid-state structures of the final products vary depending on the heteroallene inserted. The CO₂-inserted product is dimeric in the solid-state, with both bridging and chelating carbamate ligands. These dimers form a chain-like network via intermolecular Sn?O interactions. The monomeric thiocarbamate also shows a chain-like extended structure, through both Sn?O and Sn?S interactions, while the dithiocarbamate product has no significant intermolecular contacts.     

Conformational isomerism of the binuclear N,N-pentamethylenedithiocarbamate cadmium(II) complex, [Cd2{S2CN(CH2)5}4] on multinuclear (N, Cd) CP/MAS NMR and single-crystal X-ray diffraction data

Crystalline N,N-cyclo-pentamethylenedithiocarbamate (PmDtc) cadmium(II) complex was prepared and studied by means of ¹⁵N, ¹¹³Cd CP/MAS NMR spectroscopy and single-crystal X-ray diffraction. The unit cell of the cadmium(II) compound comprises two centrosymmetric isomeric binuclear molecules [Cd₂{S₂CN(CH₂)₅}₄], which display structural inequivalence in both ¹⁵N and ¹¹³Cd NMR and XRD data. There are pairs of the dithiocarbamate ligands exhibiting different structural functions in both isomeric molecules. Each of the terminal ligands is bidentately coordinated to the cadmium atom and forms a planar four-membered chelate ring [CdS₂C]; whereas pairs of the tridentate bridging ligands combine two neighbouring cadmium atoms forming an extended eight-membered tricyclic moieties [Cd₂S₄C₂], whose geometry can be approximated by a ‘chair’ conformation. The structural states of cadmium atoms were characterised by almost axially symmetric ¹¹³Cd chemical shift tensors. All experimental ¹⁵N resonance lines were assigned to the nitrogen structural sites in both isomeric binuclear molecules.     

Low-dimensional compounds containing cyano groups. XIX. Crystal structure, spectroscopic, thermal and magnetic properties of {[Cu(tn)2]3[Pt(CN)4]2}[Pt(CN)4] (tn = 1,3-diaminopropane) complex

Violet prismatic crystals of {[Cu(tn)₂]₃[Pt(CN)₄]₂}[Pt(CN)₄] (tn = 1,3-diaminopropane) were crystallized from the water-methanol solution containing CuCl₂·2H₂O, tn and K₂[Pt(CN)₄]·3H₂O. Prepared complex was characterized using elemental analysis, infrared and UV-Vis spectroscopy, magnetic measurement and thermal analysis. X-ray analysis revealed an ionic character of the complex containing mononuclear square planar [Pt(CN)₄]²⁻ complex anions and penta-nuclear [Cu(tn)₂-Pt(CN)₄-Cu(tn)₂-Pt(CN)₄-Cu(tn)₂]²⁺ complex cations. The inner Cu(II) atom of the complex cation is hexa-coordinated, whereas two crystallographically equivalent peripheral Cu(II) atoms are penta-coordinated in the shape of a deformed square pyramid. Four v(CN) absorption bands observed in the IR spectrum are in agreement with the higher number of crystallographically different cyano groups and a broad highly asymmetric band observed in the reflectance UV-Vis spectrum is consistent with the presence of both hexa- and penta-coordinated Cu(II) atoms in the structure. The temperature dependence of the inverse susceptibility suggests the presence of a weak antiferromagnetic exchange coupling between Cu(II) ions. The complex is stable up to 210 °C when its two-stage thermal decomposition starts.     

Syntheses and characterization of novel sterically demanding amido ligand derivatives and their alkali metal ion complexes, crystal structures of [SiH2Mes2], [NH(SiHMes2)2] and [Na{N(SiHMes2)2}(OEt2)]

Three bulky silanes, [SiH₂Mes₂] (1), [SiHMeMes₂] (2), SiHMes₃ (3), two novel amines, [NH(SiHMes₂)₂] (4), NH₂(SiMeMes₂) (5), and three novel alkali metal ion complexes, [Na{N(SiHMes₂)₂}(OEt₂)] (6), Li{N(SiHMes₂)₂} (7), K{N(SiHMes₂)₂} (8), have been synthesized and characterized by multinuclear NMR and mass spectroscopy. The structures of compounds 1, 4 and 6 have been determined by X-ray crystallography. The spectroscopy and structural results are discussed.