Knowledge Bank

The 1:1 complexes between $Cn(n\le 13)$ carbon clusters and the $H2O$ molecule formed in Ar matrices at 12K have been investigated $experimentally.ab$ In addition, IR absorption bands found with higher energy than the $Cn\cdot H2OC-C$ stretching bands have been assigned to 1:2 complexes with the general structure $H2O\cdot Cn\cdot H2O$, rather than $Cn\cdot (H2O)2$. The proposed structure is supported by geometry optimization and harmonic frequencies calculated at $B3LYP/6-31G\ast \ast$ level for the $Cn\cdot H2O,H2O\cdot Cn\cdot H2O$ and $Cn\cdot (H2O)2$ systems. In particular, the $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C$-labeled experimental spectra for $\mathrm{<mrow\; data-mjx-texclass="ORD">12<mrow\; data-mjx-texclass="ORD">/</mrow>13</mrow>}C5\cdot H2O$ and $\mathrm{<mrow\; data-mjx-texclass="ORD">12<mrow\; data-mjx-texclass="ORD">/</mrow>13</mrow>}C6\cdot H2O$ complexes will be presented and compared to the calculated ones at the $B3LYP/6-31G\ast \ast$ level. The $CnO$ and $C2H2$ final photoproducts observed after UV matrix photolysis will be discussed within the context of possible photo-production of these species in interstellar $space.cd$