A new synthesis for nitrosyl salts with weakly coordinating anions exemplified by NO[B(CF3)4]

A new synthesis for nitrosyl salts of weakly coordinating anions is described, using the corresponding guanidinium salts as starting materials. The guanidinium salt [C(NH2)(3)][B(CF3)(4)] was obtained by a metathesis reaction of K[B(CF3)(4)] with [C(NH2)(3)]Cl. Treatment of the guanidinium salt with liquid NO2 resulted in analytical pure NO[B(CF3)4] in quantitative yield. The guanidinium and nitrosyl tetrakis(trifluormethyl)borates were characterized by vibrational and NMR spectroscopy as well as by DSC measurements.