Figure 11: (a) Absorption spectral changes recorded at 10 min interval for the reaction between 2 (0.30x10-4 M) and NaBH4(2.34×10-4 M) in CH3OH at 322 K; (b) similar data recorded at 30 min interval for the reaction between 4 (0.15×10-4 M) and NaBH4(0.58×10-4 M) in CH3OH at 320 K; (c) similar data recorded at 2 min interval for the reaction between 2 (0.25×10-4 M) and Me3N→O (1.0×10-2 M) in CH3OH at 298 K; (d) similar data recorded at 20 min interval for the reaction between 4 (0.17×10-4 M) and Me3N →O (0.20×10-2 M) in CH3OH at 320 K.