Control of the thermal cis to trans isomerizations of azobenzene and thioindigo derivatives by the formation of supramolecular H‐bonded assemblies

2,3‐Bis(aminocyclohexyl)−6‐methoxy‐1,3,5‐triazine (1a) forms intermolecular H‐bonded complexes with 3,3′‐diacetyl‐cis‐azoenzene (4) and 6,6′‐diethoxy‐cis‐thioindigo (5b), (association constants K = 4.9 × 10⁴ and 3.5 × 10⁵ 1 mol⁻¹, respectively). The thermal cis→trans isomerization of 4b and 5b to 3,3′‐diacetyl‐trans‐azobenzene (4a), and 6,6′‐diethoxy‐trans‐thioindigo (5a), is inhibited in the intermolecular complex 1a–4b and 1a–5b. Molecular mechanics calculations support the formation of the intermolecular H‐bonded complexes between 1a and 4b or 5b.