Orientation of guest benzene molecules in Hofmann-type and related clathrates by molecular mechanics calculation

Molecular mechanics calculations were carried out to interpret the observed orientational angle of the benzene molecule enclathrated in the Hofmann-type M(NH₃)₂Ni(CN)₄·2 C₆H₆ (M = Mn, Ni, Cu, and Cd), Hofmann-en-type Cd(en)Ni(CN)₄·2 C₆H₆ (en = NH₂CH₂CH₂NH₂), and Hofmannmea-type(2) Cd(mea)Ni(CN)₄·2 C₆H₆ (mea = NH₂CH₂CH₂OH) clathrates using the van der Waals potential functions in Molecular Mechanics Version 2. The angle is most influenced by the guest-to-guest contact in the interlayer space between the two-dimensionalcatena-[metal(II) tetra--cyanonickelate(II)] networks for the Hofmann-type series. The discrepancy between the calculated and the observed angles in each crystal structure was at largest 3.5°; the structures of Cd(NH₃)₂Ni(CN)₄·2 C₆H₆ and Cd(en)Ni(CN)₄·2 C₆H₆ have been revised using new data collected by counter-methods.     

Investigation of pharmacophore and antipharmacophore features of certain dimethyltin(IV) complexes of flexible N‐protected amino acids and fluorinated β‐diketone/β‐diketones

A set of pentacoordinated dimethyltin(IV) complexes of flexible N‐protected amino acids and fluorinated β‐diketone/β‐diketones was screened for their antibacterial activity against Pseudomonas aeruginosa , Staphylococcus aureus and Streptomyces griseus . These pentacoordinated complexes of the type Me₂SnAB (where : R = CH(CH₃)C₂H₅, A₁H; CH₂CH(CH₃)₂, A₂H; CH(CH₃)₂, A₃H; CH₂C₆H₅, A₄H; and BH = R'C(O)CH₂C(O)R″: R′ = C₆H₅, R″ = CF₃, B₁H; R′ = R″ = CH₃, B₂H; R′ = C₆H₅, R″ = CH₃, B₃H; R′ = R″ = C₆H₅, B₄H) were generated by the reactions of dimethyltin(IV) dichloride with sodium salts of flexible N‐protected amino acids (ANa) and fluorinated β‐diketone/β‐diketones (BNa) in 1:1:1 molar ratio in refluxing dry benzene solution. Plausible structures of these complexes were elucidated on the basis of physicochemical and spectral studies. ¹¹⁹Sn NMR spectral data revealed the presence of pentacoordinated tin centres in these dimethyltin(IV) complexes.     

Amidrazones. VII. Formation of s-triazines by thermolysis of N1-benzyl-substituted amidrazone ylides

The preparation of ylides of the general structure is described. Thermolysis of 14a (R = CH₃, R' = H, Ar = C₆H₅) gave dimethylamine and 2,4-dimethyl-6-phenyl-s-triazine. Thermolysis of ylides 14b (R = C₆H₅; R' = CH₃, Ar = C₆H₅) and 14c (R = C₆H₅, R' = CH₃, Ar = p-tolyl) gave dimethylamine, ArCH = NCH₃ and 1-methyl-2-Ar-4,6-diphenyl-1,2-dihydro-s-triazines ( 19a,b ). Triazines 19a and 19b were also prepared by condensation of N-methylbenzamidine with benzaldehyde and p-tolualdehyde, respectively. Thermolysis of 14d (R = C₆H₅, R¹ = CH₂C₆H₅,Ar = C₆H₅) gave 1-benzyl-2,4,6-triphenyl-1,2-dihydro-s-triazine ( 19c ) and N-benzylidenebenzylamine. Mechanistic aspects of these reactions are discussed.     

Verbindungen der Seltenerdelemente mit α-4-Dimethylaminobenzoinoxim

Zusammenfassung Es wurden VerbindungenLnCl₃·H₂ DBox ^* (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb) und La₂(DBox)₃·6 CH₃OH, Pr₂(DBox)₃·6 CH₃OH, Nd₂(DBox)₃·3 C₂H₅OH, Sm₂(DBox)₃· ·3 C₂H₅OH, Gd₂(DBox)₃·3 C₂H₅OH, Tb₂(DBox)₃·2 C₂H₅OH, DyH(DBox)₂·2 C₂H₅OH, HoH(DBox)₂·2 C₂H₅OH, ErH(DBox)₂, YH(DBox)₂·H₂O isoliert. Diese wurden mittels Thermoanalyse und Röntgenstreuung untersucht sowie ihre IR-Absorptionspektren gemessen und diskutiert.

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Compounds of rare earth elements with -4-dimethylaminobenzoinoxime

The compoundsLnCl₃·H₂ DBox ^* (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb) and La₂(DBox)₃·6 CH₃OH, Pr₂(DBox)₃·6 CH₃OH, Nd₂(DBox)₃·3 C₂H₅OH, Sm₂(DBox)₃·3 C₂H₅OH, Gd₂(DBox)₃· ·3 C₂H₅OH, Tb₂(DBox)₃·2 C₂H₅OH, DyH(DBox)₂·2 C₂H₅OH, HoH(DBox)₂·2 C₂H₅OH, ErH(DBox)₂ and YH(DBox)₂·H₂O were isolated, and studied by thermoanalysis and X-ray diffraction. Their IR absorption spectra were recorded and are discussed.

     

Inclusion Compounds of Thiourea and Paralkylated Ammonium Salts. Part VII. Hydrogen-Bonded Host Lattices Constructed from Thiourea and Anionic Species Derived from Benzoic Acid

New inclusion complexes (n-C₃H₇)₄N⁺C₆H₅CO ₂ ^– · 3(NH₂)₂CS (1), (n-C₄H₉)₄N⁺[(C₆H₅CO₂)₂H]^–·6(NH₂)₂CS (2) and (C₂H₅)₄N⁺C₆H₅CO ₂ ^– ·(NH₂)₂CS (3) have been prepared and characterized by X-ray crystallography. Crystal data, MoK radiation: 1, space group P2₁2₁2₁, Z = 4, a = 8.544(3), b = 14.588(4), c = 24.448(4) Å, and R1 = 0.062 for 1536 observed data; 2, space group Pbcn, Z = 4, a = 24.938(3), b = 8.911(1), c = 23.733(9) Å, and R1 = 0.055 for 2132 observed data; 3, space group P2₁2₁2₁, Z = 4, a = 9.996(2), b = 10.122(4), c = 18.350(2) Å, and R1 = 0.049 for 1180 observed data. In the crystal structure of 1, the (n-C₃H₇)₄N⁺ cations are stacked in a single column and accommodated within each channel built up by wide thiourea ribbons and benzoate ions via N—H···O hydrogen bonds. In the crystal structure of 2, the tetrabutylammonium cations are arranged in a zigzag column within each channel built of parallel corrugated thiourea layers that are inter-linked by dimeric [(C₆H₅CO₂)₂H]^– groups through N—H·O hydrogen bonds. In compound 3 the (C₂H₅)₄N⁺ cations are accommodated in pseudo-channels generated from infinitely extended thiourea-benzoate composite ribbons.     

Magnetische Untersuchungen an Komplexen von La(III), Pr(III) und Nd(III) mitSchiffschen Basen

Specific magnetic susceptibilities (_s) of several newly synthesized chelates of some of the lanthanons [La(III), Pr(III) and Nd(III)] are reported. These derivatives are of the general type,Ln(O-i-C₃H₇)_3–n (C₆H₅CHNRO) _n [where,Ln=La(III), Pr(III) or Nd(III);n=1 or 2 and R=CH₂CH₂, CH₂CHCH₃ or C₆H₄] and have been prepared by the reaction of the alkoxides of the lanthanons withSchiff bases such as benzylidene-2-hydroxyethylamine (C₆H₅CHNCH₂CH₂OH), benzylidene-2-hydroxy-n-propylamine (C₆H₅CHNCH₂CHOHCH₃) and benzylidene-o-aminophenol (C₆H₅CHNC₆H₄OH) in different molar relations in dry benzene.The resulting crystalline derivatives are non-volatile, light to deep yellow or blackish in colour. These tend to polymerize on keeping as shown by their insoluble nature and higher melting points, the polymerisation possibly occurring by the intermolecular coordination through oxygen atoms as reported earlier¹.UsingGouy method², the bis-isopropoxy mono-Schiff base and mono-isopropoxy bis-Schiff base complexes of La(III) have been shown to be diamagnetic, with _s values being in the range of –0.32 to –0.45×10^–6 and –0.39 to –0.55×10^–6 c.g.s. units at 305 K respectively.In the remaining derivatives, Pr(O-i-C₃H₇)_3–n (C₆H₅CH NRO) _n and Nd(O-i-C₃H₇)_3–n (C₆H₅CHNRO) _n (where,n=1 or 2 and R=CH₂CH₂, CH₂CHCH₃ or C₆H₄) the magnetic moment values range between 3.25 to 3.32 and 3.30 to 3.33 _B respectively indicating their paramagnetic nature.     

Heteroatom derivatives of aziridine V. Cleaving of ethylenimine by anhydrides of monocarboxylic acids. New method of synthesizingβ-acylaminoethyl esters of organic acids

The reaction of ethylenimine with anhydrides of monocarboxylic acids (RCO)₂O gives theβ-acylaminoethyl esters of the acids RCONHCH₂CH₂OCOR, hitherto unknown (only an ester with R=Me known). When R=C₆H₅ dibenzoylaminoethyl benzoate (C₆H₅CO)₂· · NCH₂CH₂OCOC₆H₅ is also formed. The IR spectra of the compounds prepared are studied.     

Peculiarities of dissociative ionization of alkylcyclopentadienyl nitrosyl π-complexes of nickel

The decomposition of alkylcyclopentadienyl nitrosyl -complexes of nickel, (C₅H₄R)(NO)Ni (R=H, Et,i-Pr, CH₂Ph), under the action of electron impact has been studied. The nature of the nitrosyl ligand has been shown to be the factor determining the main fragmentation pathway which involves the abstraction of an NO molecule. The effect of the nature of the ligand on the ability of the molecular ion (C₅H₄R)LNi⁺ (L=C₅H₄R, C₅H₅, C₃H₅, NO) to rearrange with hydrogen atom migration from one ligand to another has been considered. The structure of the alkyl group R determines a competing fragmentation pathway involving cleavage of the -C-C bond with respect to the cyclopentadienyl ring in the substituent.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1985–1988, November, 1993.     

Tin(IV) complexes ofSchiff bases derived from salicylaldehyde and aminoalcohols

11 and 12 molar reactions of tin(IV) chloride with theSchiff bases, HO–C₆H₄CHNROH [where R=–(CH₂)₂–, –CH₂–, –CH(CH₃)–, –(CH₂)₃–, and –CH(C₂H₅)CH₂–] have been studied in different stoichiometric ratios and derivatives of the type SnCl₄(SBH₂) and SnCl₄(SBH₂)₂ (whereSBH₂ represents theSchiff base molecule) have been isolated. These have been characterised by elemental analysis, conductivity measurements and I.R. spectral studies.