The spectroscopy and photodissociation dynamics of the (A) over tilde (3)Pi and (B) over tilde (3)Sigma(-) states of the CNN radical have been investigated by fast beam photofragment translational spectroscopy. Vibronic transitions located more than 1000 cm(-1) above the (A) over tilde (3)Pi<--(X) over tilde (3)Sigma(-) origin were found to predissociate. Photofragment yield spectra for the (B) over tilde (3)Sigma(-)<--(X) over tilde (3)Sigma(-) band between 40 800 and 45 460 cm(-1) display resolved vibrational progressions with peak spacing of approximate to 1000 cm(-1) corresponding to symmetric stretch 1(0)(n) and combination band 1(0)(n)3(0)(1) progressions. Ground state products C(P-3)+N-2 were found to be the major photodissociation channel for both the (A) over tilde (3)Pi and (B) over tilde (3)Sigma(-) states. The translational energy distributions for the (A) over tilde (3)Pi state are bimodal with high and low translational energy components. The distributions for the (B) over tilde (3)Sigma(-) state reveal partially resolved vibrational structure for the N-2 photofragment and indicate extensive vibrational and rotational excitation of this fragment. These results suggest that bent geometries are involved in the dissociation mechanism and provide more accurate values: Delta(f)H(0)(CNN)=6.16 +/- 0.05 eV and Delta(f)H(298)(CNN)=6.15 +/- 0.05 eV. These values, coupled with recent D-0(RH) and D-298(RH) values from Clifford [J. Phys. Chem. 102, 7100 (1998)], yield Delta(f)H(0)(HCNN)=5.02 +/- 0.18 eV, Delta(f)H(298)(HCNN)=4.98 +/- 0.18 eV, Delta(f)H(0)(H2CNN)=3.09 +/- 0.21 eV, and Delta(f)H(0)(H2CNN)=3.09 +/- 0.21 eV.