Synthesis of methylcyclotetra(hexa)siloxanes with different reactive groups at the same silicon atom

Representatives of methylcyclotetra(hexa)siloxanes with two different reactive groups at the same silicon atom (CH₂=CH and Cl, H and Cl, CH₂=CH and OH) were synthesized for the first time by condensation of trichlorovinylsilane with dihydroxydimethylsilane, and by stepwise condensation of trichloro-and trichlorovinylsilane with 1,3-dihydroxy-1,1,3,3-tetramethyldisiloxane in the presence of amines (aniline, pyridine, and triethylamine). The condensation with 1,3-dihydroxy-1,1,3,3-tetramethyldisiloxane with a large excess of trichlorosilane, unlike the condensation with trichlorovinylsilane, occured intramolecularly to give monochlorotetramethylcyclotrisiloxane in a high yield and intermolecularly to give 1,1,7,7-tetrachloro-3,3,5,5-tetramethyl-1,7-dihydrotetrasiloxane. The structures of the synthesized compounds were confirmed by ¹H and ²⁹Si NMR spectroscopy, IR spectroscopy, and mass spectrometry. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 932–936, June, 2006.     

Spectral and thermochemical properties of the [Na(H2O)4] [EuL4]·0.775CH2Cl2 complex,HL = 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione

Reaction of Eu(NO₃)₃·6H₂O with 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione (HL) in the presence of NaOH affords the complex compound [Na(H₂O)₄] [EuL₄]·0.775CH₂Cl₂ (I). The spectral (UV, IR, ¹H NMR spectroscopy), and thermo-luminescent (TG-DSC-MS) properties of the complex I, as well as its fragmentation at the laser desorption ionization (LDI-MS) were studied.     

Mass spectra of some (Z)-α-Phenyl-β-(2-thienyl)acrylonitriles

The mass spectra of some (Z)α-(4-R′-phenyl)-β-(2-thienyl-5-R)acrylonitriles (R = H, CH₃, Br; R′ = H, CH₃O, CH₃, Cl, NO₂) at 70 eV are reported. Mass spectra exhibit pronounced molecular ions. The compound's where R = H, and CH₃ are characterized by the occurrence of a strong [M - H]⁺ peak. Moreover, in all the compounds a m/z 177 peak occurs. In the compounds where R = H, [M - HS]* and [M - CHS]* ions are present except the nitroderivatives. Where R = CH₃, [M - HS]⁺ ion occurs.     

Studies in mass spectrometry. III—formation of a common intermediate in the primary fragmentation process of 1-phenylcyclobutene and of 2-phenyl-1,3-butadiene

The mass spectra of the title compounds show peaks corresponding to the primary fragmentation of H, CH₃ and (H₂ + C₂H₂). Kinetic study suggests that the molecular ion of 1-phenylcyclobutene and 2-phenyl-1,3-butadiene loses H and CH₃ through formation of a common intermediate. This is confirmed by appearance potential and ionisation potential measurements, fragmentation of deuterium labelled compounds and the corrected Z values.     

Preparation and characterization of binuclear CuII complexes derived from diamines and dialdehydes

New macrocyclic complexes were synthesized by template reaction of 1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane, 1,4-bis(2-carboxyaldehydephenoxy)butane or 1,3-bis(2-carboxyaldehydephenoxy)propane with 1,4-bis(2-aminophenoxy)butane, 1,3-bis(2-aminophenoxy)butane, 1,4-bis(4-chloro-2-aminophenoxy)butane or 1,3-bis(4-chloro-2-aminophenoxy)butane and Cu(NO₃)₂ ·?3H₂O or Cu(ClO₄)₂ ·?6H₂O, respectively. The complexes have been characterized by elemental analysis, IR, ¹H and ¹³C NMR, UV–Vis spectra, magnetic susceptibility, conductivity measurements and mass spectra. All complexes are diamagnetic and binuclear.     

Synthesis and Characterization of New Unsymmetrically Substituted Phthalocyanines

 Unsymmetric metallophthalocyanines (M=Zn, Co, Ni) carrying alkylthio and acetyloxyethylthio groups on peripheral positions were prepared from 4,5-bis-alkylthio-phthalonitrile, 4,5-bis-(acetyloxyethylthio)-phthalonitrile, and the corresponding anhydrous metal salts Zn(CH₃COO)₂, NiCl₂, and CoCl₂. The extremely soluble compounds were characterized by their IR, ¹H NMR, and UV/Vis spectra. Their long wavelength absorption band was found to be bathochromically shifted; their solubility is superior to that of symmetrical phthalocyanines.     

Syntheses and Spectroscopic Study of Some New N‐4‐Fluorobenzoyl Phosphoric Triamides; Crystal Structures of 4‐F‐C6H4C(O)N(H)P(O)R2, R = NH‐C(CH3)3, NH‐CH2C6H5, N(CH3)(CH2C6H5)

Some new N‐4‐Fluorobenzoyl phosphoric triamides with formula 4‐F‐C₆H₄C(O)N(H)P(O)X₂, X = NH‐C(CH₃)₃ ( 1 ), NH‐CH₂‐CH=CH₂ ( 2 ), NH‐CH₂C₆H₅ ( 3 ), N(CH₃)(C₆H₅) ( 4 ), NH‐CH(CH₃)(C₆H₅) ( 5 ) were synthesized and characterized by ¹H, ¹³C, ³¹P NMR, IR and Mass spectroscopy and elemental analysis. The structures of compounds 1 , 3 and 4 were investigated by X‐ray crystallography. The P=O and C=O bonds in these compounds are anti. Compounds 1 and 3 form one dimensional polymeric chain produced by intra‐ and intermolecular ‐P=O···H‐N‐ hydrogen bonds. Compound 4 forms only a centrosymmetric dimer in the crystalline lattice via two equal ‐P=O···H‐N‐ hydrogen bonds. ¹H and ¹³C NMR spectra show two series of signals for the two amine groups in compound 1 . This is also observed for the two α‐methylbenzylamine groups in 5 due to the presence of chiral carbon atom in molecule. ¹³C NMR spectrum of compound 4 shows that ²J(P,C_aliphatic) coupling constant for CH₂ group is greater than for CH₃ in agreement with our previous study. Mass spectra of compounds 1 ‐ 3 (containing 4‐F‐C₆H₄C(O)N(H)P(O) moiety) indicate the fragments of amidophosphoric acid and 4‐F‐C₆H₄CN⁺ that formed in a pseudo McLafferty rearrangement pathway. Also, the fragments of aliphatic amines have high intensity in mass spectra.     

Conversion of 1,3‐Dimethyl‐5‐(Arylazo)‐6‐Amino‐Uracils to 1,3‐Dimethyl‐5‐(Arylazo)‐Barbituric Acids: Spectroscopic Characterization,Photophysical Property and Determination of pKa of the Products

The study of inter‐conversion between molecules, especially biologically and pharmaceutically important molecules, is extremely important. This study reports the inter‐conversion between two azo‐derivtives: azo‐6‐aminouracils to azo‐barbituric acids. We successfully converted the 1,3‐dimethyl‐5‐(arylazo)‐6‐aminouracils ( Uazo‐1 to Uazo‐4 ) to 1,3‐dimethyl‐5‐(arylazo)‐barbituric acids ( BAazo‐1 to BAazo‐4 ) (where aryl?C₆H₅‐( 1 ); p‐MeC₆H₄‐( 2 ), p‐ClC₆H₄‐( 3 ), and p‐NO₂C₆H₄‐( 4 )) following an acid‐hydrolysis path. The products were characterized using spectroscopic tools like UV‐vis, IR, and NMR spectroscopy. UV‐vis spectra of the as‐prepared dyes reveal that in contrast to the azo‐6‐aminouracils they are hardly responsive towards solvatochromism. IR spectra exhibit three characteristic >C?O frequencies for as‐prepared azobarbituric acids instead of two for mother azo‐6‐aminouracils. ¹H NMR spectra which reflect the existence of solution species evidence the absence of >C?NH group (characteristic imido‐H at the 6‐position of hydrazone species of azo‐6‐aminouracils) and consequence presence of >C?O group at the same position in as‐prepared azobarbituric acids. They exhibit structural emissions in the range of 400–440 nm upon excitation at 360 nm. The determined acid dissociation constant (pKa) values of BAazos increase according to the following sequence: BAazo ‐ 2 > 1 > 3 > 4 .     

Physicochemical study on bis-hydrazone derived from 1,3-diaminoguanidine and salicylaldehyde and its complexes with transition metals

The reaction of 1,3-diaminoguanidine with salicylaldehyde gave the corresponding bis-hydrazone, and complexes of the latter with copper(II), vanadyl(II), nickel(II), and manganese(II) of the composition LM₂X (L is triply deprotonated hydrazone, X = CH₃COO^? or pyrazole) were synthesized. Their structure was determined on the basis of elemental analyses, IR, ¹H NMR, and UV spectra, and low-temperature magnetochemical data.     

Synthesis and Characterization of Secondary Nitrosamines from Secondary Amines Using Sodium Nitrite and p‐Toluenesulfonic Acid

We synthesized nitrosamines (R₂N? NO) with R=iPr ( 1 ), nPr ( 2 ), nBu ( 3 ), and hydroxyethyl ( 4 ) from the amine using sodium nitrite/p‐toluenesulfonic acid in CH₂Cl₂. The rate of formation of 1 – 4 increases in the direction iPr<nPr<nBu2CH₂OH. Compounds 1 – 3 were obtained as colorless solids, whereas 4 is a bright yellow liquid. Compounds 1 – 4 were characterized by elemental analysis, MS, IR, and multinuclear NMR (¹H, ¹³C, and ¹⁵N) spectroscopies. Additionally, we measured the UV/Vis spectra of all compounds, which show maxima of absorption at approximately 221 nm and molar extinction coefficients between 3043 and 4859 L mol^?1 cm^?1. We calculated the optimized structures of 1 – 4 (B3LYP/6‐311+G(d,p)) and computed the NMR spectroscopic chemical shifts and infrared frequencies. Furthermore, we carried out a natural bond orbital (NBO) analysis of the nitrosamine moiety. Lastly, the compounds described in this work are valuable starting materials for the synthesis of 2‐tetrazenes with potential interest to replace highly toxic hydrazines in rocket propulsion.     

An analysis of the vibrational structure of high-resolution UV spectra and long-wave IR Fourier transform spectra in studies of internal rotation in molecules

The methods for analyzing the vibrational structure of high-resolution UV spectra and long-wave IR Fourier transform spectra in studies of internal rotation in α,β-unsaturated carbonyl compounds R₄R₃C=CR₂-COR₁ (R₁ = F, Cl; R₂ = R₃ = R₄ = H, CH₃) are compared. These methods were found to give different experimental values for systems of torsional vibration energy levels up to high quantum numbers, torsional frequencies (0–1 transitions), and anharmonicity coefficients x ₁₁ for trans and cis isomers of the same molecules in the ground electronic state (S ₀). It was shown that the experimental technique for analyzing the vibrational structure of UV spectra excludes the hydrolysis of compounds under study. Taking into account Fermi resonance and numerous Deslandres tables constructed for trans and cis isomers provides reliable determination of values necessary for the construction of internal rotation potential functions, because they are multiply repeated in various Deslandres tables. An analysis of the vibrational structure of UV spectra gives more reliable V _n internal rotation potential function parameters. The V _n parameter values were substantiated by quantum-mechanical calculations performed by other authors.     

1,3-bis(2,4,6-trinitrophenylaminooxy)propane and its 4-cyano-2,6-dinitrophenyl congener: Synthesis and properties

Starting from N-hydroxyphthalimide (5) and 1,3-dibromopropane (6) we obtained 1,3-bis(phthalimidooxy)propane (7) which led to 1,3-bis(aminooxy)propane dihydrochloride (8). From its reaction with picryl chloride or 4-cyano-2,6-dinitrochlorobenzene, the two title compounds (4b, 4a) were obtained. ¹H-NMR and ¹³C-NMR spectra are presented. For comparison with the analogous N-methoxy-2,6-dinitro-4-R-anilines 1a, 1b (R=CN or R=NO₂), wer report the hydrophobic characteristics (by RPTLC), electronic spectra for the neutral compounds and their anions, pK _a values, and the behavior towards oxidizers (DPPH, PbO₂, Pb(CH₃COO)₄, KMnO₄ and Ag₂O); DPPH converts compounds 1a, 1b and 4a, 4b into betainic structures 2a, 2b respectively.     

Palladium(II) Complexes of the Thiosemicarbazone and N‐Ethylthiosemicarbazone of 3‐Hydroxypyridine‐2‐carbaldehyde: Synthesis,Properties, and X‐Ray Crystal Structure

Two novel, stable Pd^II complexes, compounds 3 and 4 , of two 3‐hydroxypyridine‐2‐carbaldehyde thiosemicarbazones, 1 and 2 , resp., were prepared from Li₂PdCl₄. The single‐crystal X‐ray structure of complex 3 (= [Pd( 2 )Cl]) shows that the ligand monoanion coordinates in a planar conformation to the metal via the pyridyl N‐, the imine N‐, and the thiolato S‐atoms. Intermolecular H‐bonds, π–π, and CH ? ? ? π interactions lead to a two‐dimensional supramolecular assembly. The electronic, IR, UV/VIS, and NMR spectroscopic data of the two complexes are reported, together with their electrochemical properties. A sophisticated experimental procedure was used to determine the multiple dissociation constants of the ligands 1 and 2 by UV/VIS titration.     

Synthesis and characterization of Hg(II) and Zn(II) complexes based on 3-[(4-chlorophenylamido)]propenoic acid

3-[(4-Chlorophenylamido)]propenoic acid has been synthesized by reaction of maleic anhydride and 4-chloroaniline in 1:1 molar ratio in glacial acetic acid and its metal complexes have been synthesized by the reaction of 3-[(4-chlorophenylamido)]propenoic acid with HgCl₂ and [Zn(CH₃COO)₂] · 2H₂O in 2: 1 molar ratio, respectively. All the synthesized compounds have been characterized by the elemental analysis, IR, UV/Vis and NMR (¹H, ¹³C) spectroscopy. Conductance for the reported compounds has been recorded in ethanol and suggests the non-electro lytic nature of complexes. IR data of metal complexes shows that the ligand is bound to the metal via both carboxylate oxygen atoms and complexes exhibits 4-coordinated geometry in solid state. NMR (¹H, ¹³C) study confirms the structure of the 3-[(4-chlorophenylamido)]propenoic acid and the reported complexes.     

The synthesis,NMR (1H, 13C, 119Sn) and IR spectral studies of some di‐ and tri‐organotin(IV) sulfonates: X‐ray crystal structure of [(n‐C4H9)2Sn(OSO2C6H4CH3‐4)2·2H2O]

A number of alkyltin(IV) paratoluenesulfonates, R_nSn(OSO₂C₆H₄CH₃‐4)_4?n (n = 2, 3; R = C₂H₅, n‐C₃H₇, n‐C₄H₉), have been prepared and IR spectra and solution NMR (¹H, ¹³C, ¹¹⁹Sn) are reported for these compounds, including (n‐C₄H₉)₂Sn(OSO₂X)₂ (X = CH₃ and CF₃), the NMR spectra of which have not been reported previously. From the chemical shift δ(¹¹⁹Sn) and the coupling constants ¹J(¹³C, ¹¹⁹Sn) and ²J(¹H, ¹¹⁹Sn), the coordination of the tin atom and the geometry of its coordination sphere in solutions of these compounds is suggested. IR spectra of the compounds are very similar to that observed for the paratoluenesulfonate anion in its sodium salt. The studies indicate that diorganotin(IV) paratoluenesulfonates, and the previously reported compounds (n‐C₄H₉)₂Sn(OSO₂X)₂ (X = CH₃ and CF₃), contain bridging SO₃X groups that yield polymeric structures with hexacoordination around tin and contain non‐linear C? Sn? C bonds. In triorganotin(IV) sulfonates, pentacoordination for tin with a planar SnC₃ skeleton and bidentate bridging paratoluenesulfonate anionic groups are suggested by IR and NMR spectral studies. The X‐ray structure shows [(n‐C₄H₉)₂Sn(OSO₂C₆H₄CH₃‐4)₂·2H₂O] to be monomeric containing six‐coordinate tin and crystallizes from methanol–chloroform in monoclinic space group C2/c. The Sn? O (paratoluenesulfonate) bond distance (2.26(2) Å) is indicative of a relatively high degree of ionic character in the metal–anion bonds. Copyright © 2003 John Wiley & Sons, Ltd.     

Mononuclear nickel(II) and zinc(II) complexes with deprotonated forms of the tripodal hexadentate ligand 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine

In the crystal structures of both title compounds, [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]nickel(II) [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]nickel(II) chloride methanol disolvate, [Ni(C₂₆H_25.5N₃O₃)]₂Cl·2CH₄O, and [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]zinc(II) perchlorate [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]zinc(II) methanol trisolvate, [Zn(C₂₆H₂₅N₃O₃)]ClO₄·[Zn(C₂₆H₂₆N₃O₃)]·3CH₄O, the 3d metal ion is in an approximately octahedral environment composed of three facially coordinated imine N atoms and three phenol O atoms. The two mononuclear units are linked by three phenol–phenolate O—H...O hydrogen bonds to form a dimeric structure. In the Ni compound, the asymmetric unit consists of one mononuclear unit, one‐half of a chloride anion and a methanol solvent molecule. In the O—H...O hydrogen bonds, two H atoms are located near the centre of O...O and one H atom is disordered over two positions. The Ni^II compound is thus formulated as [Ni(H_1.5L)]₂Cl·2CH₃OH [H₃L is 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine]. In the analogous Zn^II compound, the asymmetric unit consists of two crystallographically independent mononuclear units, one perchlorate anion and three methanol solvent molecules. The mode of hydrogen bonding connecting the two mononuclear units is slightly different, and the formula can be written as [Zn(H₂L)]ClO₄·[Zn(HL)]·3CH₃OH. In both compounds, each mononuclear unit is chiral with either a Δ or a Λ configuration because of the screw coordination arrangement of the achiral tripodal ligand around the 3d metal ion. In the dimeric structure, molecules with Δ–Δ and Λ–Λ pairs co‐exist in the crystal structure to form a racemic crystal. A notable difference is observed between the M—O(phenol) and M—O(phenolate) bond lengths, the former being longer than the latter. In addition, as the ionic radius of the metal ion decreases, the M—O and M—N bond distances decrease.     

Metal Complexes with Biologically Important Ligands. CLXVI Tetracarbonyl Complexes of Chromium(0) and Molybdenum(0) with Schiff Bases from Pyridine‐2‐carboxaldehyde and α‐Amino Acid Esters as N,N‐Chelate Ligands

The complexes [M(CO)₄(pyridyl‐CH=N‐CHRCO₂R′)] (M = Cr, Mo; R = H, CH₃, CH(CH₃)₂, CH₂CH(CH₃)₂) were obtained by reaction of the Schiff bases from pyridine‐2‐carboxaldehyde and glycine, L‐alanine, L‐valine or L‐leucine esters with the norbornadiene complexes [M(CO)₄(nbd)] and were characterized by IR, ¹H and ¹³C NMR and UV‐vis spectra. The deeply colored complexes exhibit solvatochromism.     

Synthesis and Characterization of New Unsymmetrically Substituted Phthalocyanines

Summary.  Unsymmetric metallophthalocyanines (M=Zn, Co, Ni) carrying alkylthio and acetyloxyethylthio groups on peripheral positions were prepared from 4,5-bis-alkylthio-phthalonitrile, 4,5-bis-(acetyloxyethylthio)-phthalonitrile, and the corresponding anhydrous metal salts Zn(CH₃COO)₂, NiCl₂, and CoCl₂. The extremely soluble compounds were characterized by their IR, ¹H NMR, and UV/Vis spectra. Their long wavelength absorption band was found to be bathochromically shifted; their solubility is superior to that of symmetrical phthalocyanines. Received July 27, 1999. Accepted (revised) September 30, 1999     

Ligandenverdrängungsreaktionen von Kobalt-dicyclopentadienyl mit tertiären Phosphiten – Darstellung und Eigenschaften der Komplexe C5H5Co[P(OR)3]2

The reaction of Co(C₅H₅)₂ with tertiary phosphites mainly gives the half-sandwich type compounds C₅H₅Co[P(OR)₃]₂ (R = CH₃, C₂H₅, C₆H₅), which are characterised by means of their IR., UV., and NMR. spectroscopic data. The mass spectra of the new compounds are discussed.     

Synthesis,characterization and cytotoxic activity of 5,10,15,20‐tetrakis[4‐(triorganostannyloxy)phenyl]porphyrins

5,10,15,20‐Tetrakis[4‐(triorganostannyloxy)phenyl]porphyrins, (R₃SnO)₄TPP [2, R = Cy (a), Ph (b), PhC(CH₃)₂CH₂ (c)], have been synthesized by the condensation of 4‐(triorganostannyloxy)benzaldehyde, 4‐(R₃SnO)C₆H₄CHO (1), with pyrrole in the presence of BF₃ followed by oxidation by p‐chloranil and characterized by means of elemental analysis, IR, UV–visible and NMR (¹H, ¹³C and ¹¹⁹Sn) spectra. The results of X‐ray single‐crystal diffraction show that 1a and 1b possess a trans‐C₃SnO₂ trigonal bipyramidal geometry with the axial positions occupied by the phenolate oxygen and formyl group oxygen of an adjacent molecule and form a one‐dimensional zigzag chain. In 2a, the macrocyclic core of the porphyrin is coplanar and each tin atom possesses a distorted tetrahedral geometry. These compounds (1 and 2) have potent in vitro cytotoxic activity against two human tumor cell lines – CoLo205 and MCF‐7 – and the activity decreases in the order Ph > Cy > PhC(CH₃)₂CH₂ for the R group bound to tin. Copyright © 2013 John Wiley & Sons, Ltd.