APPLIED ORGANOMETALLIC CHEMISTRY Appl. Organometal. Chem. 2007; 21: 862–869 Published online 7 August 2007 in Wiley InterScience (www.interscience.wiley.com) DOI:10.1002/aoc.1266 Materials, Nanoscience and Catalysis Synthesis and physicochemical studies of ferrocene-containing materials Naseer Iqbal, Muhammad Saif ullah Khan, M. Adnan Saeed and Zareen Akhter* Department of Chemistry, Quiad-i-Azam University, Islamabad-45320, Pakistan Received 27 November 2006; Revised 10 February 2007; Accepted 24 March 2007 Low-temperature solution-phase polycondensation of 1,1 ′ -ferrocenedicarboxylic acid chloride with newly synthesized aromatic diamines was carried out in tetrahydrofuran in the presence of triethylamine to form several new organometallic aromatic polyamides containing ferrocene units. The organometallic aromatic polyamides derived were in good yields ranging from 75 to 80%, amorphous with melting temperatures of >350 ◦ C. The monomers and the resulting polymers were characterized by their physical properties, elemental analysis, 1 H NMR and FTIR spectroscopy. The differential scanning calorimetry and thermogravimetric studies of the resulting aramids were also carried out. All the polymers were insoluble in common organic solvents. However, all dissolved in concentrated H 2 SO 4 forming reddish brown solutions. Their glass transition temperatures were quite high, which is characteristic of aramids. They were also stable up to 450 ◦ C with 10% mass losses (14 – 23%) recorded in the range 400 – 470 ◦ C. The activation energies for decomposition of each aramid were also calculated using the Horowitz and Metzger method. All polymers showed reduced solution viscosities in concentrated sulphuric acid, which may be attributed to non-Newtonian behavior. Copyright  2007 John Wiley & Sons, Ltd. KEYWORDS: ferrocene; organometallic aramids; polyamides INTRODUCTION Aromatic polyamides also known as ‘aramids’ are based on aromatic diamines 1 and characterized as very high temperature resistant materials with a favorable balance of other physical and chemical properties. 2 Recently, many studies 3–6 have focused on introducing ether-containing and bulky pendant groups along the aramid backbone to minimize the tradeoff between the processability and properties. The introduction of ether linkages enhances the processability and toughness without a significant reduction in thermal stability. The incorporation of a bulky pendant group decreases interchain hydrogen bonding interactions and generally disturbs the co-planarity of aromatic units to reduce packing densities and crystallinity. This should enhance solubility and maintain high glass- transition temperatures (T g ) through controlled segmental mobility. 7 *Correspondence to: Zareen Akhter, Department of Chemistry, Quiad-i-Azam University, Islamabad-45320, Pakistan. E-mail: zareenakhter@yahoo.com Contract/grant sponsor: Quaid-i-Azam University, Islamabad. Ferrocene, among organometallic compounds, is the most promising candidate for incorporation of metal into polymer structures due to its well-characterized redox behavior and excellent photochemical and thermal stability. 8–12 Ferrocene polymers are useful for several applications, e.g. manufacture of electronic devices like microelectrochemical diodes, 13 formation of redox gels that show charge transfer properties, 14 modification of electrodes, 15 construction of amperometric biosensors 16 and more recently in the area of non-linear optical (NLO) materials. 17 In a continuation of our previous work, 18 we report here the effects of different amines with ferrocene into the aramid backbone using low-temperature solution poly- condensation. We have synthesized three new aromatic diamines having flexible ether linkages along with steri- cally bulky groups to determine the effects of chain flexibility and bulkiness of the side groups on the basic properties of these organometallic aramids. Solubilities in common organic solvents, thermal stability and thermal degrada- tion kinetics were studied, along with elemental and Fourier transform IR (FTIR) spectroscopic characterization. Solubility Copyright  2007 John Wiley & Sons, Ltd.