Reactions of bicyclic tertiary amines, 1,4-diazabicyclo[2.2.2]octane (DABCO) and quinuclidine, have been carried out with tetrachlorocyclodicarbaphosphatriazene, (ClCN)₂(Cl₂PN), and with (ClCN)₂(Cl₂PN) together with another acyclic tertiary amine. Reaction of an acyclic tertiary amine [NEt₃, N(n-Pr)₃, NEt(i-Pr)₂ or Me₂NCH₂NMe₂] with the chlorocarbaphosphazene followed by DABCO in 1∶1∶1 molar ratio proceeds with cleavage of a C–N bond of both tertiary amines. The cleaved alkyl group of DABCO remains as an alkyl chloride on the product molecule. The 4-(2-chloroethyl)piperazino derivatives of carbaphosphazenes, (R₂NCN)[ClCH₂CH₂N(CH₂CH₂)₂NCN](Cl₂PN) [R₂N = NEt₂ 1, N(n-Pr)₂ 2, NEt(i-Pr) 3 or NMe₂ 4] were isolated, purified and characterized by spectral and analytical methods. Reaction of (ClCN)₂(Cl₂PN) with two moles of DABCO gave the compound [ClCH₂CH₂N(CH₂CH₂)₂NCN]₂(Cl₂PN) 5. The 4-(2-chloroethyl)piperidino compound [ClCH₂CH₂CH(CH₂CH₂)₂NCN]₂(Cl₂PN) 6 was obtained in the reaction of (ClCN)₂(Cl₂PN) with two moles of quinuclidine, while (Me₂NCN)[ClCH₂CH₂CH(CH₂CH₂)₂NCN](Cl₂PN) 7 is the product in its reaction with Me₂NCH₂NMe₂ and quinuclidine in 1∶1∶1 molar ratio. The crystal structure of compound 4 has been determined and shows differences in the exocyclic N–C bond distances of the piperazino group in its bonding to the 2-chloroethyl and carbaphosphazene moieties.