There are disclosed compounds having the formula ##STR1## wherein R and R' are selected from the group consisting of (a) substituents having the formula R.sup.1 R.sup.2 R.sup.3 C-wherein R.sup.1 is H or an alkyl group of 1 to 6 carbon atoms, and R.sup.2 and R.sup.3 are independently alkyl of 1 to 6 carbon atoms; (b) phenyl group; (c) phenyl group substituted by Br, Cl, F, alkyl group of 1 to 10 carbon atoms, or alkoxy group of 1 to 10 carbon atoms; and (d) an adamantyl group; and M is As or Sb; with the proviso that when R and R' are phenyl or substituted phenyl in which the substituents are in meta or para positions, M is As. Preferably R and R' are the same and are t-butyl, phenyl or adamantyl. The compounds display thermochromic properties.
The reaction of amino ketones with titanium tetrachloride/zinc powder has been studied in tetrahydrofuran and 1,4-dioxane under an argon atmosphere. Symmetrical 1,8-diaminoalkenes 2 were obtained from the corresponding Mannich base hydrochlorides 1 via the intermolecular reductive coupling, and azacycloalkenes 4 were prepared from diketoamines 3 via the intramolecular reductive coupling under similar conditions.