Fig. 1.

Synthetic routes and chemical structures of compounds. Synthetic routes of 60° diplatinum (II) acceptor 8 (A) and bis-ammonium linker 4 (B). Conditions: a) hexethylene glycol ditosylate, K₂CO₃, CH₃CN, reflux, 72 h; 64%; b) Pt(PEt₃)₄, toluene, 95 °C, 72 h; 68%; c) AgOTf, dry CH₂Cl₂, room temperature, 12 h; 95%; d) (4-formylphenyl)boronic acid, K₂CO₃, Pd(PPh₃)₄, dioxane/water (2:1), 90 °C, 48 h; 63%; e) (i) n-butylamine, CH₃OH, reflux, 12h; (ii) NaBH₄, room temperature, 24 h; (iii) HCl (aq), and (iv) NH₄PF₆ (aq); 27% in four steps.