## Materials and Methods
### [Pt(bpy\({}^{\prime\prime}\)E1-H)(Me)(Pph\({}_{3}\))][Br\({}_{4}\)], 8a-Bf\({}_{4}\)  
To a solution of **6a** (98.0 mg, 0.149 mmol) in acetone (2\({}^{13}\)C NMR (CDCl\({}_{3}\)): \(\delta\) = \(-\)13.14 (d with sat, JPt\({}_{\text{C}}\) = 723 Hz, \({}^{2}\)J\({}_{\text{P-C}}\) = 5.1 Hz, Pt-CH\({}_{3}\)); 52.95 (s, OCH\({}_{3}\)); 111.60 (d with sat, J = 5.6, 56.1 Hz); 123.25 (s with sat); 128.26 (d); 130.19 (d); 132.36 (d with sat); 135.04 (d with sat); 137.33 (s); 143.08 (s with sat); 149.85 (s, Cq); 150. 41 (d with sat); 151.06 (s, Cq); 161.67 (s, Cq); 162.22 (s with sat, Cq); 164.96 (d with sat, Cq). _2.12. [_Pt(bpy\({}^{61*}\))(Me)(PPh\({}_{3}\))][BF\({}_{4}\)]_, **9b**-BF\({}_{4}\)  
To a solution of **6b** (30.0 mg, 0.0458 mmol) in acetone (15 mL), solid [H\({}_{3}\)O:18-crown-6] [BF\({}_{4}\)] was added (17.2 mg, 0.0465 mmol). The solution was stirred at room temperature for 1 h, then it was concentrated to small volume, treated with diethyl ether and filtered. Yield: 64%. M.p. = 123 \({}^{\circ}\)C.  
Anal. Calcd. for C\({}_{31}\)H\({}_{30}\)BF\({}_{4}\)N\({}_{2}\)PPt: C, 50.08%; H, 4.07%; N, 3.77%. Found C, 49.92%; H, 3.95%; N, 3.54%. \({}^{1}\)H NMR (CDCl\({}_{3}\)) = 0.80 (d with sat, 3H, J\({}_{\text{H-H}}\) = 7.3 Hz, \({}^{2}\)J\({}_{\text{P-H}}\) = 82.5 Hz, Pt-CH\({}_{3}\)); 1.46 (t, 3H, J\({}_{\text{H-H}}\) = 7.6 Hz, CH\({}_{3}\) Et); 3.18 (q, 2H, J\({}_{\text{H-H}}\) = 7.6 Hz, CH\({}_{2}\) Et); 6.90 (m, 1H, J\({}_{\text{H-H}}\) = 6.6 Hz, H\({}_{5}\)); 7.52-7.41 (m, 10H, H PTh\({}_{3}\)); 7.56 ppm (d with sat, 1H, J\({}_{\text{H-H}}\) = 7.7 Hz, \({}^{4}\)J\({}_{\text{P-H}}\) = ca 14 Hz, H\({}_{5}\)); 7.75-7.86 (m, 5H, H PPh\({}_{3}\)); 7.85 (d with sat, 1H, J\({}_{\text{H-H}}\) = 5.8 Hz, \({}^{3}\)J\({}_{\text{P-H}}\) = 13 Hz, H\({}_{6}\)); 8.10 (t, 1H, J\({}_{\text{H-H}}\) = 8.0 Hz, H\({}_{4}\)); 8.69 (d, 1H, J\({}_{\text{H-H}}\) = 8.2 Hz, H\({}_{3}\)); 8.85 (dd with sat, 1H, \({}^{4}\)J\({}_{\text{P-H}}\) = 5.2 Hz, J\({}_{\text{H-H}}\) = 7.8 Hz, \({}^{3}\)J\({}_{\text{P-H}}\) = 51 Hz, H\({}_{4}\)); 13.2 (s br, N-H). \({}^{31}\)P NMR (CDCl\({}_{3}\)): \(\delta\) = 31.2 (s with sat, 1P, J\({}_{\text{P-P}}\) = 2400 Hz, Pt-P). _2.13. [Pt(bpy\({}^{61*}\))(Cl)(PPh\({}_{3}\))][BF\({}_{4}\)]_, **100**-BF\({}_{4}\)  
To a solution of **7b** (30.3 mg, 0.0448 mmol) in acetone (15 mL), solid [H\({}_{3}\)O:18-crown-6] [BF\({}_{4}\)] was added (17.2 mg, 0.0465 mmol). The solution was stirred to room temperature for 1 h, then it was concentrated to small volume, treated with diethyl ether and filtered. Yield: 89%. M.p. (dec) = 243 \({}^{\circ}\)C. Anal. Calcd. for C\({}_{30}\)H\({}_{2}\)BCIF\({}_{4}\)N\({}_{2}\)PPt: C, 47.17%; H, 3.56%; N, 3.67%. Found, 47.33%; H, 3.79%; N, 3.46%. \({}^{1}\)H NMR (CDCl\({}_{3}\)): \(\delta\) = 1.35 (t, 3H, J\({}_{\text{H-H}}\) = 7.7 Hz, CH\({}_{3}\) Et); 3.06 (q, 2H, J\({}_{\text{H-H}}\) = 7.7 Hz, CH\({}_{2}\) Et); 6.79 (d, 1H, J\({}_{\text{H-H}}\) = 8.3 Hz, H\({}_{5}\)); 6.79 (d, 1H, J\({}_{\text{H-H}}\) = 8.3 Hz, H\({}_{5}\)); 7.56-7.49 (m, 2H, H\({}_{\text{P}^{\prime}}\) andH\({}_{4}\)); 7.81-7.69 (m, H PTh\({}_{3}\)); 8.32 (t, 1H, J\({}_{\text{H-H}}\) = 7.8 Hz, H\({}_{4}\)); 8.80 (d, 1H, J\({}_{\text{H-H}}\) = 7.8 Hz, H\({}_{3}\)); 10.0 (m with sat, 1H, \({}^{3}\)J\({}_{\text{P-H}}\) = 30.2 Hz, H\({}_{6}\)); 13.3 (s br, N-H). \({}^{31}\)P NMR (CDCl\({}_{3}\)): \(\delta\) = 19.59 (s with sat, 1P, J\({}_{\text{P-P}}\) = 4139 Hz, Pt-P). _2.14. Reaction between_ **1a**_, [Pt(bpy\({}^{6}\)OMe-H)(Me)DMSO], and [H\({}_{3}\)O:18-crown-6][BF\({}_{4}\)]_  
The reaction between **1a** and [H\({}_{3}\)O:18-crown-6] [BF\({}_{4}\)] was performed under the same conditions of the analogous reaction of complex **1b**. The reaction was also followed by means of \({}^{1}\)H NMR. Despite several attempts, we were not able to identify the reaction products, with the exception of a singlet at 0.17 ppm (acetone \(d_{6}\)), attributed to free methane. **3. Results**  
_3.1.