I was asked to determine the coordination compound which has the name:
$$\text{triamminetrinitritocobalt(I)}$$
I thought it must be: $$\ce{[Co(NH3)3(ONO)3]^2-}$$
The $-2$ charge can be deduced by adding up the oxidation numbers.
However, in this case, shouldn't the name be written as cobaltate instead of cobalt? Where is my mistake and what did I miss here?