A dinucleating 1,8-naphthyridine ligand featuring fluorene-9,9-diyl-linked phosphino side arms (PNNP) was synthesized and used to obtain the cationic dicopper complexes , [(PNNP)Cu(μ-Ph)][NTf]; [NTf] = bis(trifluoromethane)sulfonimide, , [(PNNP)Cu(μ-CCPh)][NTf], and , [(PNNP)Cu(μ-OBu)][NTf]. Complex reacted with diboranes to afford dicopper μ-boryl species (, with μ-Bcat; cat = catecholate and , with μ-Bpin; pin = pinacolate) that are more reactive in C(sp)-H bond activations and toward activations of CO and CS, compared to dicopper μ-boryl complexes supported by a 1,8-naphthyridine-based ligand with di(pyridyl) side arms. The solid-state structures and DFT analysis indicate that the higher reactivities of and relate to changes in the coordination sphere of copper, rather than to perturbations on the Cu-B bonding interactions. Addition of xylyl isocyanide (CNXyl) to gave , [(PNNP)Cu(μ-Bcat)(CNXyl)][NTf], demonstrating that the lower coordination number at copper is chemically significant. Reactions of and with CO yielded the corresponding dicopper borate complexes (, [(PNNP)Cu(μ-OBcat)][NTf]; , [(PNNP)Cu(μ-OBpin)][NTf]), with demonstrating catalytic reduction in the presence of excess diborane. Related reactions of and with CS provided insertion products , {[(PNNP)Cu][μ-SC(Bcat)]}[NTf], and , [(PNNP)Cu(μ,κ-SCBpin)][NTf], respectively. These products feature Cu-S-C-B linkages analogous to those of proposed CO insertion intermediate.