Pentane moiety is incorporated through N, N termini of carbazole (Cz) and designed 1,5-Bis[N-Carbazolyl] pentane (BNCP). Theoretically time dependent DFT (TD-DFT) has been employed to observe geometries, electronic and optical properties of BNCP, which elaborated the strong π-π stacking effect, a prerequisite phenomenon to build the crystalline polymer. The designed monomer which has mp 78 °C and fully characterized by FT-IR spectroscopy has been polymerized using FeCl3.6H2O into poly(1,5-[biscarbazolyl] pentane) (PBNCP). During synthesis monomer to oxidizing agent (OA) ratios; 1:4, 1:6 and 1:8 have been used to investigate the effect on structure, morphology and properties. These samples were designated as PBNCP 1:4, PBNCP 1:6 and PBNCP 1:8. Each PBNCP sample under XRD characterization expressed crystalline nature as predicted by TD-DFT. Similarly, SEM revealed well defined slabs like beams with progressively increase of dimensions as compared to PCz, which is quite granular. The optical behavior of 1,5-BNCP and its polymers appeared red shifted with greater molar absorptivity. Photoluminescence (PL) study of 1,5-BNCP and all PBNCP samples displayed improved light harvesting trend as compared to Cz and PCz. The pentane spacer as an internal plasticizer decreased glass transition (Tg) from 233 °C in PCz to 178 °C in all PBNCP. In cyclic voltammetry (CV) oxidation appeared at current density 0.07<InlineEquation ID="IEq3"> <EquationSource Format="TEX">\(\:\times\:\)</EquationSource> </InlineEquation>10−5, 2.61<InlineEquation ID="IEq4"> <EquationSource Format="TEX">\(\:\times\:\)</EquationSource> </InlineEquation>10−5, and 1.2<InlineEquation ID="IEq5"> <EquationSource Format="TEX">\(\:\times\:\)</EquationSource> </InlineEquation>10−5 A about 1 V for these samples. The reduction occurred at current density − 2.60<InlineEquation ID="IEq6"> <EquationSource Format="TEX">\(\:\times\:\)</EquationSource> </InlineEquation>10−5, -6.66<InlineEquation ID="IEq7"> <EquationSource Format="TEX">\(\:\times\:\:\:\)</EquationSource> </InlineEquation>10−5 and − 3.02V<InlineEquation ID="IEq8"> <EquationSource Format="TEX">\(\:\times\:\)</EquationSource> </InlineEquation>10− 5A, under same pattern. All PBNCP have shown high thermal stability, photosensitivity, optical and redox properties as compared to PCz.

Experimental vis DFT study of 1,5-Bis(N-Carbazolyl) pentane cum oxidative polymerization with enhanced photosensitivity and electrochemical trends

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发表日期：

2026年4月16日

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Shahla Iftikhar,
Zahoor Ahmad,
Zaroon Sajid,
Khalil Ahmad,
Motahira Hashmi,
Ick Soo Kim,
Syeda Tahira Naqvi,
Sana Ullah

摘要

Pentane moiety is incorporated through N, N termini of carbazole (Cz) and designed 1,5-Bis[N-Carbazolyl] pentane (BNCP). Theoretically time dependent DFT (TD-DFT) has been employed to observe geometries, electronic and optical properties of BNCP, which elaborated the strong π-π stacking effect, a prerequisite phenomenon to build the crystalline polymer. The designed monomer which has mp 78 °C and fully characterized by FT-IR spectroscopy has been polymerized using FeCl₃.6H₂O into poly(1,5-[biscarbazolyl] pentane) (PBNCP). During synthesis monomer to oxidizing agent (OA) ratios; 1:4, 1:6 and 1:8 have been used to investigate the effect on structure, morphology and properties. These samples were designated as PBNCP 1:4, PBNCP 1:6 and PBNCP 1:8. Each PBNCP sample under XRD characterization expressed crystalline nature as predicted by TD-DFT. Similarly, SEM revealed well defined slabs like beams with progressively increase of dimensions as compared to PCz, which is quite granular. The optical behavior of 1,5-BNCP and its polymers appeared red shifted with greater molar absorptivity. Photoluminescence (PL) study of 1,5-BNCP and all PBNCP samples displayed improved light harvesting trend as compared to Cz and PCz. The pentane spacer as an internal plasticizer decreased glass transition (Tg) from 233 °C in PCz to 178 °C in all PBNCP. In cyclic voltammetry (CV) oxidation appeared at current density 0.07 \(\:\times\:\) 10⁻⁵, 2.61 \(\:\times\:\) 10⁻⁵, and 1.2 \(\:\times\:\) 10⁻⁵ A about 1 V for these samples. The reduction occurred at current density − 2.60 \(\:\times\:\) 10⁻⁵, -6.66 \(\:\times\:\:\:\) 10⁻⁵ and − 3.02V \(\:\times\:\) 10^− 5A, under same pattern. All PBNCP have shown high thermal stability, photosensitivity, optical and redox properties as compared to PCz.