The aim of this proposal is to study the internal structure of novel organometallic polymers based on two metal-containing moieties -Ru, Au (or Ag)- bridged through a tridentate phosphine (PTA). Interestingly, X-ray and light scattering experiments have demonstrated that the polymer associates in aqueous solution forming stable micro-particles, which exhibits gel properties, specifically a thermal controlled size transition. Due to their physical and chemical properties, this environment sensitive polymer network is a promising material for industrial and biological applications i.e. smart catalysis, drug delivery or chemical sensing, where a deep knowledge of the structure is necessary. We are submitting for LOQ beamtime to investigate the expected nano-structural changes of the internal polymer network, associated to the microparticle size transition always detected by light scattering