Synthesis and mesomorphic properties of iron(II)-containing dendrimeric complexes derivative of 3,4-n-dodecyloxybenzoyl poly(propylene imine)

ABSTRACT

Synthesis and characterisation of liquid crystalline (LC) Fe(II) complexes with ‘two-chain’-substituted poly(propylene imine) (PPI) dendrimeric ligand of the first to fifth generations are presented. Compounds were synthesised by complex formation between the metal salt and the corresponding dendrimeric ligands. The purity and structure were proved by different methods. The calculated amount of iron in the complexes was confirmed by the experimental data with a great degree of precision. Iron ions are incorporated into the dendrimer at two sites: at the border and inside of the dendrimeric core. A tetragonal coordination of iron was found. Mesomorphic properties of dendrimer iron(II) complexes were studied, a hexagonal columnar mesophase (Col_h) was evaluated by the results of X-ray scattering. Upon excitation at absorption bands, iron dendrimeric complexes exhibit fluorescence properties.

GRAPHICAL ABSTRACT

KEYWORDS:

• Liquid crystalline complexes
• dendrimers
• hexagonal columnar mesophase
• iron(II)
• fluorescent properties

Acknowledgements

This work was supported by the grant of Russian Foundation for Basic Research No. 14-03-31280-mol_a and the grant of the President of the Russian Federation (No. MK-70.2014.3). Authors wish to thank Dr Markus Bate (Bayreuth University, Germany) for measuring mass spectroscopy MALDI-TOF-MS and help with optical investigations of our compounds. NMR, FTIR spectroscopy and DSC analysis were carried out by the instrumentality of equipment of Interlaboratory Scientific Center «Verhnevolzhskij Region Center of Physicochemical Researching».

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No potential conflict of interest was reported by the authors.

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Funding

This work was supported by the grant of Russian Foundation for Basic Research [No. 14-03-31280-mol_a] and the grant of the President of the Russian Federation [No. MK-70.2014.3].