Application of FTIR-ATR spectroscopy to confirm the microwave assisted synthesis and curing of Cashew nut shell liquid derived nanostructured materials

The present work reports the development of nanostructured material from Cashew nut shell liquid (CNSL, an agro byproduct of cashew industry, 87% cardanol) to evaluate their potential in antibacterial applications as a substitute of petroleum feedstock via an energy-efficient method. The nanostructured material was synthesized by coordination polymerization reaction of cardanol and divalent Mn(II) salt with the aid of microwave irradiations. FTIR spectroscopy was used to confirm the proposed structure of the synthesized materials. FTIR-ATR spectroscopy was employed to verify the curing of material by comparing the spectra of the cured samples with the frequencies of uncured samples. Magnetic moment and UV-visible spectroscopy were used to confirm the proposed structure of the material further. Morphology of the synthesized material was investigated by XRD, optical microscopy, SEM and TEM and thermal behaviour by TGA/DTG/DSC technique. Agar diffusion method was utilized to investigate the antibacterial activity of the synthesized material against bacterial strains E. coli, K. pneumoniae, B. subtilis and S. aureus. N₂ adsorption-desorption was investigated to check BET specific surface area and BJH pore size distribution of the same. The results revealed that the synthesized materials were obtained as semicrystalline, porous, thermally stable and nanostructured film forming materials with moderate to good antibacterial activity against different nosocomial bacteria. They can be used as thermally stable antibacterial agents in the field of films/coatings for health care applications.

A novel one-dimensional coordination polymer of cadmium(II)/triazine extending by di-chloro and di-iodo bridges

A new triazine ligand salt, 2,2′,2″-(1,3,5-triazine-2,4,6-triyl)tris(hydrazin-1-ium) chloride [THT·(HCl)3], and the one-dimensional coordination polymer of cadmium, [Cd2( µ-THT)( µ-Cl)( µ-I)I2]·2(H2O), are prepared and characterized by elemental analysis, Fourier-transform infrared spectroscopy, 1H NMR spectroscopy, and single-crystal X-ray diffraction (for the cadmium polymer). X-ray analysis revealed that the polymeric backbone is extended alternatively by di-iodo and di-chloro bridges; this type of bridge is not observed previously between any metal atoms. There are two types of cadmium atoms in the polymer: cadmium of the polymeric chain and terminal cadmiums. The geometry around the first (CdN2Cl2I2) is octahedral, while the latter (CdN3I2) has an incline to square-pyramidal geometry. The triazine ligand of this structure also bridges two cadmium atoms and acts as an N3 donor toward the terminal cadmium atoms and as an N2 donor toward the cadmium atoms of the chain. In the crystal network of the cadmium polymer, the hydrogen bonds of N–H···X (X: O, N, I) form different hydrogen bond motifs, including [Formula: see text](8), [Formula: see text](10), [Formula: see text](14), [Formula: see text](18), [Formula: see text](20), [Formula: see text](24), [Formula: see text](28), and [Formula: see text](32).

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.

Synthesis, characterization and solid state conductivity of nano-size ionic Schiff base polymers of Cu2+, Zn2+ and VO2+ containing viologen moieties

The new nano size ionic metallo-Schiff base polymers (IMSPs) were synthesized by reaction of Schiff base ligand of L and VO (acac)₂, ZnCl₂ and CuCl₂. The solid state conductivity measurements candidate them as new metallo-organic semiconductors.

Synthesis, vibrational spectrometry and thermal characterizations of coordination polymers derived from divalent metal ions and hydroxyl terminated polyurethane as ligand

A series of novel coordination polyurethanes [HTPU-M, where M=Mn(II) 'd⁵', Ni(II) 'd⁸', and Zn(II) 'd¹⁰'] have been synthesized to investigate the effect of divalent metal ions coordination on structure, thermal and adsorption properties of low molecular weight hydroxyl terminated polyurethane (HTPU). HTPU-M have been synthesized in situ where, OH group of HTPU (synthesized by the condensation polymerization reaction of ethylene glycol (EG) and toluene diisocyanate (TDI) in presence of catalyst) on condensation polymerization with metal acetate in presence of acid catalyst synthesized HTPU-M followed by coordination of metal ions with hetero atoms. The structure, composition and geometry of HTPU-M have been confirmed by vibrational spectrometry (FTIR), ¹H NMR, elemental analysis and UV-Visible spectroscopy. Morphological structures of HTPU-M were analyzed by X-Ray Diffraction analysis (XRD), Field Emission Scanning Electron Microscope (FE-SEM) with Energy Dispersive X-ray spectroscopy (EDX) and High Resolution Transmission Electron Microscope (HR-TEM) techniques. The thermal degradation pattern and thermal stability of HTPU-M in comparison to HTPU was investigated by thermal-gravimetric (TG)/differential thermal (DT), analyses along with Integral procedure decomposition temperature (IPDT) by Doyle method. The molecular weight of HTPU was determined by gel permeation chromatography (GPC). The preliminary adsorption/desorption studies of HTPU-M for Congo red (CR) was studied by batch adsorption techniques. The results indicated that HTPU-M have amorphous, layered morphology with higher number of nano-sized grooves in comparison to HTPU. Coordination of metal to HTPU plays a key role in enhancing the thermal stability [HTPU-Ni(II)>HTPU-Mn(II)>HTPU-Zn(II)>HTPU]. The HTPU-M can be utilized for industrial waste water treatment by removing environmental pollutants.

Development of bio-derived nanostructured coordination polymers based on cardanol–formaldehyde polyurethanes with ‘d5’ Mn(ii) and ‘d10’ Zn(ii) metal nodes: synthesis, characterization and adsorption behavior

Using renewable resources like cardanol aiming towards development of bio-derived coordination polymers with nanoporous layered morphology, amorphous/crystalline behavior, and better thermal stability having moderate adsorption capacity towards dye.