Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The nitrosonium ion is NO+, the nitrogen atom is bonded to an oxygen atom with a bond order of 3, the overall diatomic species bearing a positive charge. This ion is usually obtained as the following salts: NOClO4, NOSO4H (nitrosyl sulfuric acid, more descriptively written ONSO2OH), and NOBF4. The ClO 4 and BF 4 salts are slightly soluble in CH3CN. NOBF4 can be purified by sublimation at 200 250 °C and 0.01 mmHg (1.3 Pa). NOBF4 is a convenient oxidant because the byproduct NO is a gas, which can be swept from the reaction using a stream of N2. Upon contact with air, NO forms NO2, which can cause secondary reactions if it is not removed. NO2 is readily detectable by its characteristic orange color.