Organometallic Pt(II) and Pd(II) polymers containing 2,6-diethynyl 4-nitroaniline bridging spacer and related dinuclear model complexes

The metal?carbon coupling in dehydrohalogenation conditions between Pt(II) or Pd(II) square planar bisphosphine dichloride complexes and 2,6-diethynyl-4-nitroaniline (DENA) yielded organometallic polymers, i.e., ?[M(PTol3)2(?CC?R?CC?)]n? with R = p-NH2C6H2NO2 and M = Pt(II) or Pd(II). Dinuclear platinum complexes were also synthesized as geometrical models. The polymers and complexes were fully characterized by means of spectroscopic techniques. Accurate investigations with 2D nuclear magnetic resonance (NMR) spectroscopy were used to define the chemical and spatial structure of the polymeric chains as a helical conformation for both Pt(II)- and Pd(II)-based organometallic polymers. Optical absorption studies and X-ray photoelectron spectroscopy measurements revealed the extent of conjugation and the nature of the ending groups.