The present work is aimed at designing novel organometallic push-pull species. To this end, different transition metal complexes, mainly based on Fischer type carbene complexes, have been synthesized and fully characterized. Their associated photophysical properties have been analysed in detail by means of experimental and computational tools. In this regard, A-Pi-D-Pi-A push-pull systems (where A = Fischer carbene complex) with enhanced Pi-conjugation have been prepared (Chapter 1). In addition, Fischer carbene complexes have been attached to the BODIPY core (Chapter 2) or to its periphery (Chapter 3) to modulate the photophysical properties of the fluorophore. Novel transition metal-BODIPY complexes having tunable emissive properties were prepared through N-directed C-H activation/cyclometallation reaction (Chapter 4). Finally, a systematic investigation of the influence of the bulkiness of the ligands on the Pd-catalyzed self-dimerization reaction of alkoxychromium(0) (Fischer) carbene complexes has been carried out (Chapter 5). Chapter 1. Chapter 1 describes the preparation of novel Pi-extended alkoxy Fischer bis(carbene) complexes A-Pi-D-Pi-A by the reaction of the corresponding dialdehydes with alkoxychromium(0) and alkoxytungsten(0) carbene complexes following the standard conditions reported by Aumann (Scheme 1)...