Conformational Analysis of Poly(N-vinylcarbazole) by NMR Spectroscopy and Molecular Modeling

Abstract

NOESY experiments and molecular mechanics calculations have been used to examine the solution conformation of the synthetic polymer poly(N-vinylcarbazole) (PNVC). The diagonal and cross-peak volumes of theoretical NOESY spectra have been calculated for several mixing times by employing the complete relaxation matrix analysis (CORMA) introducing as structural models for the polymer chain conformation the triad stereochemical sequences (isotactic, heterotactic, and syndiotactic). Comparison between measured volumes and volumes calculated from the proposed structures allowed an assessment of the validity of the model structures. The data do not support a single conformational model, and only conformational averaging between different model structures can provide satisfactory agreement between theoretical and experimental parameters. On the basis of the conformational preference of the bulky carbazole groups of PNVC in the various stereochemical sequences, some useful conclusions were derived in relation to the photophysical behavior of this commercial polymer.

Atom transfer radical polymerization of N‐vinyl carbazole: Optimization to characterization

“…The resonance signals of the backbone methylene carbon split into three peaks at ∼33, 35, and 38 ppm, which were assigned to isotactic (mmm), heterotactic (mrm, mmr, and rrm), and syndiotactic (rrr) tetrads, respectively. The value of σ, defined by Bovey38 and Coleman,39 was found to be 0.25, which is in agreement with the value found for the homopolymers synthesized by free‐radical polymerization,40, 41 hence indicating that the reactivity and the stereochemistry of a growing radical obtained by controlled and conventional techniques are equivalent. Hence, the ATRP of VCz follows a free‐radical mechanism (Scheme ).…”

A Comparative Investigation Between Poly(N-vinylcarbazole) and Poly(3,6-N-vinylcarbazole): Spectroscopy, Conductivity, Thermal and Optical Properties

“…These bands were assigned to the H 1 , H 2 , H 8 , H 3 , H 7 , H 6 , H 4 and H 5 aromatic protons of the carbazole group of PVK, respectively, according to Karali et al [46]. The two broad signals at δ = 3.15 and 3.4 ppm and the broad signals between δ = 0.7 and 2.5 ppm are due to the aliphatic protons (CH and CH 2 , respectively) of the polymer backbone [41,[46][47][48][49][50]. Because of the poor solubility of the P3,6NVKs in organic solvents, their spectra were recorded in gel (HRMAS).…”

One-step synthesis to photoelectric hybrid composite of N-vinylcarbazole–methyl acrylate copolymer and ZnO nanocrystals via nanocrystals-initiated polymerization

“…Hybrid composite materials of organic semiconductor polymers and inorganic nanocrystals, which exhibit different properties from those of individual components, have attracted much attention from the researchers in the field of photoelectric materials [1]. Poly(N-vinylcarbazole) (PVK), one of important semiconductor polymers, has good hole-transporting ability [2], which originates from p-stacking alignment of the pendent carbazole groups [3]. Composites of PVK and nanocrystals can find applications as functional layers in photoconductive devices and solar cells [4][5][6][7][8].…”