Structural Modulation from 1D Chain to 3D Framework: Improved Thermostability, Insensitivity, and Energies of Two Nitrogen-Rich Energetic Coordination Polymers

Two new energetic coordination polymers (CPs) [Pb(BT)(H2O)(3)](n) (I) and [Pb-3(DOBT)(3)(H2O)(2)](n). (4H(2)O)(n) (2) with 1D and 3D structures were synthesized by employing two rational designed ligands, 1H,1'H-5,5'-bitetrazole (H2BT) and 1H,1'H-[5,5'-bitetrazole]-1,1'-diol ligands (DHBT), respectively. Thermal analyses and sensitivity tests show that the 3D architecture reinforces the network of 2 which has higher thermal stability and lower sensitivity than that of I. Through oxygen-bomb combustion calorimetry the molar enthalpy of formation of 2 is derived to be much higher than that of 1 as well as the reported CPs. Herein, more importantly, the heats of detonation (Delta H-det) were calculated according to the decomposition products of TG-DSC-MS-FTIR simultaneous analyses for the first time. The calculated results show that Delta H-det, of 2 is 23% higher than that of I. This research demonstrates that 3D energetic CP with outstanding energetic properties can be obtained through efficient and reasonable design.