The correct statement(s) regarding the binary transition metal carbonyl compounds is(are) (Atomic numbers : $$Fe = 26,Ni = 28$$)

Treatment of benzene with $$CO/HCl$$ in the presence of anhydrous $$AlC{l_3}/CuCl$$ followed by reaction with $$A{c_2}O/NaOAc$$ gives compound $$X$$ as the major product. Compound $$X$$ upon reaction with $$B{r_2}/N{a_2}C{O_3},$$ followed by heating at $$473$$ $$K$$ with moist $$KOH$$ furnishes $$Y$$ as the, major product. Reaction of $$X$$ with $${H_2}/Pd$$-$$C,$$ followed by $${H_3}P{O_4}$$ treatment gives $$Z$$ as the major product.

The compound $$Z$$ is

The compounds(s) which generate(s) $${N_2}$$ gas upon thermal decomposition below $${300^ \circ }C$$ is (are)

Based on the compounds of group $$15$$ elements, the correct statement(s) is (are)