Chemical compositions of five <i>Planck</i> cold clumps

Aims. Interstellar molecules form early in the evolutionary sequence of interstellar material that eventually forms stars and planets. To understand this sequence, it is important to characterize chemical composition its first steps. Methods. In paper, we present result a 2 3 mm survey five cold clumps identified by Planck mission. We carried out radiative transfer analysis on detected lines order put some constraints physical conditions within cores molecular column densities. also performed models reproduce observed abundances each source using gas-grain model Nautilus. Results. Twelve were detected: H CO, CS, SO, NO, HNO, HCO + , HCN, HNC, CN, CCH, CH OH, CO. Here, CCH only carbon chain two sources. Radiative analyses CO constrain cloud with limited success. The sources have density larger than 10 4 cm −3 temperature lower 15 K. derived species densities are not very sensitive uncertainties conditions, factor 2. different seem significant differences spreading over one magnitude. these poorer Taurus Molecular Cloud 1 Cyanopolyyne Peak (TMC-1 CP) core. Our reproduces observational upper limits for 79–83% our ‘best’ times be smaller those TMC-1, indicating may less evolved explaining numerous non-detections. Also, CS HCN always overestimated models.