Molecular machines are omnipresent in Nature, e.g. ATPase motors, and have inspired scientist for decades in their endeavor to control motion at the molecular scale, which resulted in an impressive collection of artificial nanomachinery. The crossover in contemporary chemistry shifting from static molecules towards dynamic, responsive molecular networks unambiguously shows the potential of molecular machines. This dissertation focuses on visible-light-activated functional systems, which includes triplet photosensitizers, chiroptical switches and rotary motors. In Chapter 1, the latest advances in the field of molecular photoswitches and motors activated by visible light are highlighted. Chapter 2 reports a novel type of hydrazone-based boron difluoride complex used as triplet photosensitizers for the generation of singlet oxygen. In chapter 3, we describe the design and synthesis of visible light-activated BINOL-derived chiroptical switches based on boron integrated hydrazone complexes. Upon instalment of a non-planar[a,d]-cycloheptene moiety in hydrazone ligand’s lower half, the enantiopure chiroptical switches exhibit major chiroptical changes in the CD read-out after visible light irradiation. Chapter 4 reports our efforts towards the design and synthesis of molecular switching systems based on multiple stimuli responsive chiral, tetracoordinated boron-integrated hydrazone complexes capable of adapting distinctive states. In chapter 5, a series of all-visible light-driven first generation molecular motors based on the salicylidene Schiff base functionality is presented. This simple structural modification of the first generation motor scaffold led to remarkable redshifts up to 100 nm compared to conventional motor designs. Chapter 6 describes the synthetic endeavor towards a unidirectional rotary motor governed by a phosphorus stereogenic centre.