New distannanes containing the chiral 2-(4-isopropyl-2-oxazolinyl)-5-phenyl ligand

The N-coordinated tin hydrides containing the chiral 2-(4-isopropyl-2-oxazolinyl)-5-phenyl ligand in the presence of catalytic amounts of tetrakis(triphenylphosphine)palladium gave the corresponding distannanes in good yields. The distannanes have been fully characterized by means of the ¹H, ¹³C, ¹⁵N and ¹¹⁷Sn NMR measurements. The J(¹⁵N-^117/119Sn), J(¹¹⁷Sn-¹¹⁹Sn) couplings and single-crystal X-ray analysis of distannane 3 revealed a tendency towards penta-coordination at the tin center as a result of the Sn-N interaction.     

Structural assignment of organotin hydrides containing the oxazoline ligand

A series of triorganotin hydrides and diorganotin dihydrides containing the optically active 2-(4-isopropyl-2-oxazolinyl)-5-phenyl ligand have been characterized by means of the multinuclear low-temperature NMR investigations, the results of which are discussed. In the corresponding organotin hydrides values of the ¹J(¹H-^117/119Sn) couplings appeared to be temperature dependent, supporting an axial/equatorial position of the hydrogen attached to the tin.     

Diastereoselective formation of chiral iridium hydrides containing the chiral P,N-chelate ligand (4S)-2-(2-(diphenylphosphino)phenyl)-4-isopropyl-1,3-oxazoline

The iridium complex [Ir(mu-Cl)(PN)(PPh3)]2 (1) reacts with H2 affording only the kinetic isomer OC-6-55-C of the dihydride [IrClH2(PN)(PPh3)] (2) and with methanol yielding, also exclusively, the thermodynamic isomer OC-6-53-C (2b) of the same dihydride; complex 2b has been characterised by X-ray diffractometric methods.     

(Carb)2SnF4 (Carb = 2, 3‐Dihydro‐1, 3‐diisopropyl‐4, 5‐dimethylimidazol‐2‐yliden – ein Carbenkomplex des vierwertigen Zinns

2, 3‐Dihydro‐1, 3‐diisopropyl‐4, 5‐dimethylimidazol‐2‐ylidene ( 1 , Carb) reacts with tin tetrafluoride to give the complex (Carb)₂SnF₄ ( 3 ). The ligand properties of 1 are discussed in terms of the crystal structure and NMR data of 3 .     

Synthesis and Structural Characterization of new Tri (2-methyl-2- phenylpropyl) tin Carboxylates containing Germanium

Organotincompoundsareextensivelystudiedfortheirbiologicalactivity'.Organogermaniumisanotherkindofelementthathasawiderangeofbiologicalactivity=.Tolinkbiologicalactivepropertiesoforganotinandorganogermaniumcompounds.wehavepreviouslyreportedthebiologicalactivityoftrialkyltingermylpropionates'andanticanceractivityofdibutyltindigermylpropionates'.ItiswellknownthatTorque(his[tri(2-methyl-2-phenylpropyl)tin]oxide)iswidelyusedinagricultureasanacaricide.Inthispaper,asthecontinuationofourpreviouswork"'…     

Experimental,DFT and Theoretical Corrosion Study for 4-(((4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazole-3-yl)thio)methyl)-7,8-dimethyl-2H-chromen-2-one

In this work, 4-(((4-ethyl-5-(thiophen-2-yl)-4H-1,2,4-triazole-3-yl)thio)methyl)-7,8-dimethyl-2H-chromen-2-one was synthesized by acetone-mediated condensation of 4-ethyle-5-(thiophen-2-yl)-4H-1,2,4-triazole-3-thiol and 4-(chloromethyl)-7,8-dimethyl-2H-chromen-2-one. The molecule results (3) were experimentally characterized using FT-IR, ¹H-, and ¹³C NMR spectroscopy. Density Functional Theory (B3LYP/cc-pVDZ) was used to investigate the ideal molecule structure, vibrational frequencies, and ¹H with ¹³C NMR (theoretically) chemical shifts. Theoretical and experimental spectroscopy results were compared and agreed with each other, which indicated the validity of the used developed molecular structure. The Dipole moment, hardness, softnes, electronegativity, electrophilicity index, nucleophilicity index, and chemical potential as electronic structural parameters linked to corrosion inhibition efficacy were investigated for the prepared compound. Furthermore, the fraction of transferred electrons was calculated to determine the interaction between the iron surface and organic molecules. The results indicated a favorable relationship between organic-based corrosion inhibitors and quantum chemical parameters processes. The corrosion inhibitors' behavior can be predicted without the need for experimental investigation.     

Dynamic stereochemistry of hypervalent silicon, germanium and tin compounds containing amidomethyl C, O-chelating ligands

The results of NMR-spectroscopy studies of the structure, dynamic stereochemistry, and intermolecular interactions in solutions of organic derivatives of penta-and hexacoordinated silicon, germanium, and tin containing amidomethyl, lactamomethyl, and related bidentate ligands are surveyed. For the series of works “Dynamic stereochemistry of hypervalent compounds of silicon, germanium, and tin,” the author was awarded the Academia Europea Prize for young scientists from CIS in 1996. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1912–1934. November, 1997.     

The structure and dynamics of FeH(DMPE)2(BH4), FeH(DEPE)2(BH4) and FeH(DPrPE)2(BH4): Iron complexes containing monodentate borohydride ligands

FeH(DMPE)₂(BH₄) [DMPE = 1,2-bis(dimethylphosphino)ethane] is a stable, diamagnetic complex which can be synthesized readily by borohydride reduction of FeH(DMPE)₂Cl or by treatment of Fe(DMPE)₂H₂ with borane. The complex contains an unsupported B? H? Fe hydrogen bridge. Analogous complexes with bulkier ligands, FeH(DEPE)₂(BH₄), [DEPE = 1,2-bis(diethylphosphino)ethane] and FeH(DPrPE)₂(BH₄) [DPrPE = 1,2-bis(di-n-propylphosphino)ethane], are less stable. In all complexes, in solution the borohydride ligand undergoes rapid internal motion, with all four boron-bound hydrogens interchanging environments. The barriers for BH₄ reorientation (measured by NMR spectroscopy) are in the sequence FeH(DMPE)₂(BH)₄ > FeH(DEPE)₂(BH)₄ > FeH(DPrPE)₂(BH₄).     

New bridging tridentate bis-cyclopentadienyl ligands [C5Me4(CH2)n]2PPh (n = 1, 2) for organometallic synthesis

Preparative procedures were developed for the synthesis of new transmethylated bis-cyclopentadienyl ligands with phosphine-containing bridging fragments. These ligands were isolated as the dilithium salts Li₂[(C₅Me₄CH₂)₂PPh] (1) and Li₂[(C₅Me₄CH₂CH₂)₂PPh] (3). Phosphorus-substituted 3-ansa-zirconocene dichloride [(C₅Me₄CH₂)₂PPh]ZrCl₂ was synthesized starting from 1. The NMR spectroscopic data provide evidence for the absence of the Zr←P coordination interaction in solution. A straightforward approach to 5-ansa-zirconocene dichloride [(C₅Me₄CH₂CH₂)₂PPh]ZrCl₂ starting from lithium salt 3 and ZrCl₄ was shown to be impossible. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1775–1779, September, 2007.     

Tricarbonylrhenium(I) and manganese(I) complexes of 2-(pyrazolyl)-4-toluidine

A series of tricarbonyl rhenium(I) and manganese(I) complexes of the electroactive 2-(pyrazolyl)-4-toluidine ligand, H(pzAn^Me), has been prepared and characterized including by single crystal X-ray diffraction studies. The reactions between H(pzAn^Me) and M(CO)₅Br afford fac-MBr(CO)₃[H(pzAn^Me)] (M = Mn, 1a; Re, 1b) complexes. The ionic species {fac-M(CH₃CN)(CO)₃[H(pzAn^Me)]}(PF₆) (M = Mn, 2a; Re, 2b) were prepared by metathesis of 1a or 1b with TlPF₆ in acetonitrile. Complexes 1a and 1b partly ionize to {M(CH₃CN)(CO)₃[H(pzAn^Me)]⁺}(Br⁻) in CH₃CN but retain their integrity in less donating solvents such as acetone or CH₂Cl₂. Each of the four metal complexes reacts with (NEt₄)(OH) in CH₃CN to give poorly-soluble crystalline [fac-M(CO)₃(μ-pzAn^Me)]₂ (M = Mn, 3a; Re, 3b). The solid state structures of 3a and 3b are of centrosymmetric dimeric species with bridging amido nitrogens and with pyrazolyls disposed trans- to the central planar M₂N₂ metallacycle. In stark contrast to the diphenylboryl derivatives, Ph₂B(pzAn^Me), none of the tricarbonyl group 7 metal complexes are luminescent.     

Easily prepared chiral scorpionates: tris(2-oxazolinyl)boratoiridium(i) compounds and their interactions with MeOTf

Optically active C 3-symmetric monoanionic ligands are uncommon in organometallic chemistry. Here we describe the synthesis of readily prepared tris(4 S-isopropyl-2-oxazolinyl)phenylborate [To (P)] and fluxional, zwitterionic four- and five-coordinate iridium(I) compounds [Ir(To (P))(eta (4)-C 8H 12)] ( 4) and [Ir(To (P))(CO) 2] ( 5). The highly fluxional nature of 4 and 5 makes structural assignment difficult, and the interaction between the iridium(I) center and the [To (P)] ligand is established by solid-state and solution (15)N NMR methods that permit the direct comparison between solution and solid-state structures. Although iridium cyclooctadiene 4 is a mixture of four- and five-coordinate species, the dicarbonyl 5 is only the five-coordinate isomer. The addition of electrophiles MeOTf and MeI provides the oxazoline N-methylated product rather than the iridium methyl oxidative addition product. N-Methylation was unequivocally proven by through-bond coupling observed in (1)H- (15)N HMBC experiments.     

Syntheses and Crystal Structures of Two New Open‐Framework Tin(II) Phosphates: Sn5O2(PO4)2 and Sn4O(PO4)2

Two new three‐dimensional neutral open‐framework tin(II) phosphates, Sn₅O₂(PO₄)₂ and Sn₄O(PO₄)₂, were synthesized under hydrothermal conditions with different ratio of tin(II) oxalate, phosphoric acid and 4,4′‐diaminodiphenylmethane. Their crystal structures have been solved by single‐crystal X‐ray diffraction methods. Sn₅O₂(PO₄)₂ crystallizes in the space group and contains six‐membered ring and twelve‐membered ring channels running parallel to the b axis. Sn₄O(PO₄)₂ crystallizes in the space group P2₁/n and contains intersecting eight‐membered ring channels. These two compounds have rare trigonal‐planar Sn₃O.     

Polynitrogen chemistry: preparation and characterization of (N5)2SnF6, N5SnF5, and N5B(CF3)4

Metathetical processes were used to convert N5SbF6 into N5[B(CF3)4] and (N5)2SnF6. The latter salt is especially noteworthy because it contains two N5+ ions per anion, thus demonstrating that salts with touching polynitrogen cations can be prepared. This constitutes an important milestone towards our ultimate goal of synthesizing a stable, ionic nitrogen allotrope. The stepwise decomposition of (N5)2SnF6 yielded N5SnF5. Multinuclear NMR spectra show that in HF the SnF5- ion exists as a mixture of Sn2F(10)(2-) and Sn4F(20)(4-) ions. Attempts to isolate FN5 from the thermolysis of (N5)2SnF6 were unsuccessful, yielding only the expected decomposition products, FN3, N2, trans-N2F2, NF3, and N2.     

The hindered inversion of the seven-membered ring inN-(chlorodimethylgermylmethyl)- andN-(chlorodimethylstannylmethyl)hexahydroazepin-2-ones

The stereochemical flexibility ofN-(chlorodimethylgermylmethyl)- andN-(chlorodimethylstannylmethyl)hexahydroazepin-2-ones was studied by dynamic NMR spectroscopy. Protons of the NCH₂M and MMe₂ groups (M=Ge, Sn) were shown to be anisochronic at low temperatures (<−70°C). The free activation energy of the process resulting in chemical equivalence of the protons indicated was determined. The anisochronicity of signals observed is due to the restricted inversion of the seven-membered cycle. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2379–2381, November, 1998.     

High Lithium Ionic Conductivity in the Lithium Halide Hydrates Li3‐n(OHn)Cl (0.83≤n≤2) and Li3‐n(OHn)Br (1≤n≤2) at Ambient Temperatures

Lithium ionic conductivity and phase transitions in a series of lithium halides hydrates and hydroxides with general formula Li_3‐n(OH_n)X (0.83≤n≤2; X=Cl,Br) were studied using impedance measurements and ¹H and ⁷Li NMR spectroscopy. All compounds studied in this work crystallize in the antiperovskite structure or are closely related to this structure type. With the exception of LiCl?H₂O, all compounds with integer lithium content exhibit good lithium ionic conductivity in their high temperature cubic phases above T=33 °C. Lithium doping of samples LiX?H₂O and Li₂(OH)X leads to a suppression of the phase transition into the noncubic phases and the good ionic conductivity is extended down to lower temperatures (T<0 °C). Thus, lithium doping of the lithium halide hydrates provides a promising tool for tailoring the ionic conductivity at ambient temperatures to its optimum value.     

Heterocyclic compounds from 3-(4-phenyl) benzoyl propionic acid

3-(4-Phenyl) benzoyl propionic acid was used as the starting material for the synthesisof furanones (2), pyrrolinones (5), pyridazinones (7), benzoxazinones (8) and quinazolinones (9-11). The behaviour of the derivatives of furanones and benzoxazinones toward different nucleophiles is reported.     

Enantioselective self-assembly of bimetallic [Mn(II) (delta)-Cr(III)(C2O4)3]- and [Mn(II) (lambda)-Cr(III)(C2O4)3]- layered anionic networks templated by the optically active (Rp)- and (Sp)-[1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5]+ ions

The ferrocenic ammonium (Rp)- and (Sp)-[1-CH2NR(3-)-2-CH3-C5H3Fe-C5H5] iodide salts with R=CH3, C2H5, n-C3H7, n-C4H9, were synthesized starting from the (Rp)- and (Sp)-[1-CH2N(CH3)2-2-CH3-C5H3Fe-C5H5] amines obtained in their optically active forms through asymmetric cyclopalladation of [C5H5Fe-C5H4CH2N(CH3)2]. 1H NMR studies of these planar chiral 1,2-disubstituted ferrocenic ammonium iodide salts in the presence of the (Delta)-(tris(tetrachlorobenzenediolato)phosphate(V) anion), [(Delta)-Trisphat] support the formation of specific diastereomeric ion pairs. Such intermolecular interactions can be related to the self-assembly of the two-dimensional optically active compounds [[(Sp)-1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5][Mn (Delta)-Cr(C2O4)3]] and [[(Rp)-1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5][Mn (Lambda)-Cr(C2O4)3]] starting from the resolved (Rp)- and (Sp)-[1-CH2N(n-C3H7)3-2-CH3-C5H3Fe-C5H5]+ ion associated to the racemic anionic building block rac-[Cr(C2O4)3]3- and Mn2+. Both enantiomeric forms of the networks behave as ferromagnets with a Curie temperature of 5.7 K.