Surface functionalization of phosphazenenanosphere derivatives by Schiff-base-assisted metal complexes through a Si-spacer Abbas Tarassoli *, Tahereh Sedaghat, Zeinab Ansari-Asl Department of Chemistry, College of Science, Shahid Chamran University, Ahvaz, Iran 1. Introduction In recent years, nanoscale materials with various structure and morphology have received profound interest from the theoretical or practical points of view [1–3]. These compounds exhibit unique physical and chemical properties for industrial uses [4–6] and show a great potential for the biomedical applications [7–10]. Up to date, research on this fascinating field of study has led to the preparation, characterization and application of a considerable number of organic–inorganic hybrid nanomaterials; such as nanospheres, nanoparticles, nanotubes, nanofibers and micromaterials [11–14]. Various techniques and strategies have also been employed to produce different kind of nanostructured materials. Among these, perhaps the synthesis of metal on cyclophosphazenenanosphere in particular is a promising trial [15,16]. Some important advantages of using phosphazenes over other known inorganic–organic hybrid are their excellent thermal stability, flexibility, biodegradability and biocompatibility. Thus, these materials possess a great potential in the application of biomedical and industrial area [17–20]. The starting material for almost all phosphazene reactions is usually hexachlorocyclotriphosphazene (NPCl 2 ) 3 . Various organometallic derivatives have been prepared by functionalization of (NPCl 2 ) 3 through a facile substitution reaction and the products were simply characterized by 31 P NMR technique and have been used as ligands for the metal ions [21–25]. However, there are a few reports on using phosphazene at the nano- and microscale. The synthesis of polyphosphazenenano- and microstructures through precipitation polymerization of cyclotriphosphazene without any stabilizers has successfully been reported recently [26–33]. The main objective of this research work, is to immobilize N,N 0 -bis(salicylidene)diethy- lenetriamine (H 2 saldien) Schiff base on the surface of phosphaze- nenanosphere (PNS) by (3-chloropropyl)trimethoxysilane as a Si- linker and spacer. The designed PNS–Si–H 2 saldien system could be a novel and simple approach for loading metals in a variety of coordination modes. 2. Experimental 2.1. Materials All the chemicals and reagents were purchased from Merck company except salicylaldehyde and (3-chloropropyl)trimethox- ysilane which were supplied from Alfa Aesar and hexachlorocy- clotriphosphazene and MnCl 2 Á4H 2 O from Aldrich company. 2.2. Instrumentation The IR spectra of the synthesized compounds were recorded on FTBOMEM MB102 Fourier-transform spectrophotometer (FT-IR), using KBr pellets. Thermogravimetric–differential thermal analy- sis (TG–DTA) was obtained on Perkin-Elmer S2 instrument. The XRD patterns were taken on Philips X’PertPro diffractometer (Cu Ka radiation, l = 1.54184 A ˚ ). The Scanning Electron Microscopy (SEM) images were obtained on a EM-3200 (at an activation voltage of 25 kV). The EDX patterns were recorded on Cambridge S360 SEM. The amounts of metal ions that coordinated to the Journal of Industrial and Engineering Chemistry 20 (2014) 2287–2291 A R T I C L E I N F O Article history: Received 12 August 2013 Accepted 3 October 2013 Available online 16 October 2013 Keywords: Surface functionalization Phosphazenenanosphere Metal-coordinated Schiff base Si-spacer Morphology and thermal stability A B S T R A C T Surface functionalization of organometallic derivatives of phosphazenenanosphere (PNS) by the metal- coordinated Schiff base through (3-chloropropyl)trimethoxysilane as a silicon linker and spacer was investigated. The PNS’s derivative of 4,4 0 -sulfonyldiphenol (BPS) was added to Si–H 2 saldien under ultrasonic irradiation. Metal ion (Mn 2+ , Ni 2+ or Zn 2+ ) was loaded on the PNS–Si–H 2 saldien as desired metal salt. The structure and morphology was characterized by means of FT-IR, TGA, SEM, EDX and X-ray diffraction. The average diameters of nanosphere compounds are in the range of 250–300 nm. ß 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved. * Corresponding author. Tel.: +98 611 3331042; fax: +98 611 3337009. E-mail addresses: tarassoli@scu.ac.ir, tarasoli@yahoo.com (A. Tarassoli). Contents lists available at ScienceDirect Journal of Industrial and Engineering Chemistry jou r n al h o mep ag e: w ww .elsevier .co m /loc ate/jiec 1226-086X/$ – see front matter ß 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.jiec.2013.10.003