Nanographene‐Doped Chalcone Derivatives of Dioxybiphenyl‐Bridged Dispirocyclotriphosphazenes: Synthesis, Electrical Properties, and DFT Calculations

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Abstract The cyclotriphosphazenes, which constitute an important class of inorganic compounds, can show new properties in the medical or technological fields depending on the properties of the substituted organic/inorganic groups. Herein, we aimed to determine electrical and theoretical properties of the nanographene‐doped chalcone derivatives of dioxybiphenyl‐bridged dispiro‐cyclotriphosphazenes. For this aim, a new series of chalcone substituted spiro‐cyclotriphosphazenes ( 3 a – g ) have been synthesized by the reaction of dioxybiphenyl‐bridged dispiro‐cyclotriphosphazene ( 3 ) with chalcone derivatives ( 1 a – g ), respectively. Then, nanographene was doped to these spiro‐cyclotriphosphazene 3 a – g using a hydrothermal system. The dielectric constant and loss factor of 4 % graphene‐doped chalcone‐substituted spiro‐cyclotriphosphazene 3 g were determined as 167 and 2147 at 1 kHz, respectively, showing a significant increase compared to compound 3 g . The energy values of HOMO and LUMO orbitals are computed using DFT theory's level of B3LYP/6‐31G(d,p). The FMO's energy gap values for 3 a – g were found to be 7.92, 3.48, 3.26, 3.33, 3.53, 4.03 and 3.75 eV, respectively. Especially at frequencies below 10 kHz, the most striking result was observed for the nanographene‐doped 3 d . While the AC conductivity of 3 d at 1 kHz was 3.87×10 −9 S cm −1 , the conductivity of the graphene‐doped 3 d was calculated as 5.00×10 −6 S cm −1 . In addition, DC conductivity measurements were completed as a function of temperature and linearly increasing graphs were obtained with temperature. The activation energies calculated from the slopes of these graphs were 0.293, 0.305, 0.364 and 0.920 eV for 3 c , 3 d , 3 e and 3 g , respectively.