Synthesis,Mesomorphic and Computational Characterizations of Nematogenic Schiff Base Derivatives in Pure and Mixed State

Homolog series based on three aromatic rings bearing terminal alkoxy chain of various lengths named 4-(4-(alkoxy)phenylimino)methyl)phenyl nicotinate (An) were synthesized. The alkoxy-chain length changed between 6, 8 and 16 carbons. Mesomorphic and optical properties were carried out via differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Elemental analyses, FT-IR and NMR spectroscopy were carried out to elucidate the molecular structures of the prepared derivatives. Mesomorphic results indicated that all the synthesized homologs (An) are monomorphic possessing the nematic (N) phase enantiotropically with wide thermal stability. Computational simulations were measured via density functional theory (DFT) theoretical calculation tool. The estimated thermal and geometrical parameters are in agreement with the experimental data. By discussing the estimated parameters, it was found that the molecular architecture, dipole moment and the polarizability of the investigated compounds are highly affected by the length of the attached terminal flexible chain and the location of the nitrogen atom in the other terminal aromatic ring. Binary phase diagrams of two corresponding homologs with different proportionating terminals were constructed, and their binary phase physical properties were discussed in terms of the temperature range and stability of the N phase.     

Synthesis,characterization, inequivalency of methylene proton and proton lability in the amino ligand of trans-[dichloro[(N-ferrocenyl methyl)amine](eta2-ethene)platinum] complexes

A series of complexes of the type trans-[PtCl(2)(eta(2)-ethene)(N-ferrocenyl methyl)amine)] complexes, N-ferrocenylmethylamine=[(eta(5)-C(5)-H(5))Fe(eta(5)-C(5)-H(4)CH(2)NHR], R=(Me, Pr(i), Bu(s), Bu(t), CH(2)Ph, (p-OCH(3))Ph, (o-(OCH(3))Ph, (p-CH(3))Ph, (o-CH(3))Ph, (m-CH(3))Ph, (p-Cl)Ph) have been synthesized and characterized on the basis of elemental analysis, IR, 1H and 13C NMR spectroscopic methods. The CpCH(2)NHR (Cp=(eta(5)-C(5)H(5))Fe(eta(5)-C(5)H(4)), region of the 1H NMR spectrum of the complexes has been investigated and shown to contain inequivalent methylene protons, NH-CH and 195Pt-N-CH coupling take place.     

Unusual coupling constants n J(195Pt—1H) and Pt↼H—C interactions in new Schiff base complexes of N-alkyl-1-(ferrocen-1-yl)methanimine

A series of novel ferrocenylimine complexes of platinum(II) ethene of general formula trans-[PtCl₂( ²-C₂H₄) (imine)], imine = N-alkyl-1-(ferrocen-1-yl)methanimine, (alkyl = Me; i-Pr, i-Bu, s-Bu, t-Bu, ±CH(Me)Ph, CH₂Ph and Ph) have been prepared and characterized by elemental analysis, i.r, ¹H-, ¹³C-n.m.r. spectra (¹⁵N- and ¹⁹⁵Pt-n.m.r. in part). Unusual coupling constants ³ J(¹⁹⁵Pt—¹H), 92–98 Hz were observed between the imino proton H₆ and platinum(II) which are too large for three bond coupling constants, thereby suggesting a PtH—C interaction.