Abstract Lipophilic, linear cobalt(II) triazole complex Co(1)3Cl2 in chloroform shows sol-to-gel transition upon addition of long-chained alcohols. Binding of alcohol molecules induces coordination structure changes (octahedral, Oh to tetrahedral, Td), which promotes aggregation of nanofibers and concomitant physical gelation. The surface of lipophilic, linear complexes provides binding sites for guest molecules, which is referred to as adaptive molecular clefts.