  We review the reactions between carbon chain molecules and radicals, namely
Cn, CnH, CnH2, C2n+1O, CnN, HC2n+1N, with C, N and O atoms. Rate constants and
branching ratios for these processes have been re-evaluated using experimental
and theoretical literature data. In total 8 new species have been introduced,
41 new reactions have been proposed and 122 rate coefficients from
kida.uva.2011 (Wakelam et al. 2012) have been modified. We test the effect of
the new rate constants and branching ratios on the predictions of gas-grain
chemical models for dark cloud conditions using two different C/O elemental
ratios. We show that the new rate constants produce large differences in the
predicted abundances of carbon chains since the formation of long chains is
less effective. The general agreement between the model predictions and
observed abundances in the dark cloud TMC-1 (CP) is improved by the new network
and we find that C/O ratios of 0.7 and 0.95 both produce a similar agreement
for different times. The general agreement for L134N (N) is not significantly
changed. The current work specifically highlights the importance of O + CnH and
N + CnH reactions. As there are very few experimental or theoretical data for
the rate constants of these reactions we highlight the need for experimental
studies of the O + CnH and N + CnH reactions, particularly at low temperature.
