Development of coordination polyureas derived from amine terminated polyurea and metal ions having ‘d⁵’, ‘d⁷’, ‘d⁸’ and ‘d¹⁰’ orbitals: From synthesis to applications

Amine terminated polyureas [ATPUa] were synthesized by ‘in situ’ condensation polymerization of toluene diisocyanate (TDI) with equimolar ratio of ethylene diamine (ED) and water. Incorporating the completely half-filled {Mn(II) d⁵}, partially filled {Co(II) d⁷, Ni(II) d⁸} and fulfilled {Zn(II) d¹⁰} divalent metal ions in APTUa generated the coordination polyureas (CPa). The structure and geometry of resulting CPa was ascertained by spectral techniques, the Fourier transform (FTIR), UV–Visible and nuclear magnetic resonance (¹H NMR) spectroscopy. Amorphous/semi-crystalline and rough/layered surface morphology was analyzed by X-ray diffraction analysis (XRD) and field emission scanning electron microscopy along with energy dispersive X-ray spectroscopy (FESEM/EDX). Good thermal stability was observed having the trend, ATPUa-Zn(II) > ATPUa-Mn(II) > ATPUa-Co(II) > ATPUa-Ni(II) > ATPUa [with IPDT values, 712 °C of ATPUa-Zn(II), 673 °C of ATPUa-Mn(II), 582 °C of ATPUa-Co(II), 563 °C of ATPUa-Ni(II), 488 °C of ATPUa] respectively. It was analyzed by thermo-gravimetric, differential thermal, differential scanning calorimetry and integral procedure decomposition temperature analysis (TGA/DTA/DSC/IPDT). Good adsorption/desorption behavior of CPa was analyzed with the help of batch adsorption techniques, and it was found that CPa {in order; ATPUa-Ni(II) > ATPUa-Mn(II)}can be used as effective dye adsorbent (up to 97%) for the waste water treatment. The CPa were screened for their in-vitro antimicrobial activity against six gram positive and three gram negative bacterial strains as compared to standard drug (Ciprofloxacin and Gentamicin) and moderate antimicrobial activity was observed.