Long-chain hydrocarbon molecules in the interstellar medium: search for 1-cyanobut-3-ene-1-yne, CH2=CH-C triple bond C-C triple bond N

In order to understand the implications of the apparently high abundance of long polyynes in the ISM, some molecules which are closely related chemically are being studied. A radio search for 1-cyanobut-3-ene-1-yne, CH2=CH-Ctriple bondC-Ctriple bondN, which is very closely related to HCtriple bondC-Ctriple bondC-Ctriple bondN, the first polyyne to be detected, has yielded an upper limit to the abundance. The data suggest that the chemical processes which give rise to interstellar molecules are biased towards the production of highly unsaturated organic species. The implication of this and other results is discussed with regard to the chemistry of the ISM and future investigations of these important processes. (author)