Synthesis of poly(cyclodiborazane)s by allylboration polymerization of dicyano compounds with trimethallylborane

Allylboration polymerization of α, ω-dicyanoalkanes with trimethallylborane produced the corresponding poly(cyclodiborazane)s in high yields. This polymerization includes the allylboration reaction of cyano groups and the following dimerization of iminoborane species. The intermediate iminoborane species were detected by IR measurement. The poly(cyclodiborazane)s obtained were found to be more stable toward air than those prepared by allylboration polymerization using triallylborane.