Bulk Inclusions of Pyridazine-Based Molecular Rotors in Tris(o-phenylenedioxy)cyclotriphosphazene (TPP)

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388963%3A_____%2F16%3A00466267" target="_blank" >RIV/61388963:_____/16:00466267 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1002/adfm.201600437" target="_blank" >http://dx.doi.org/10.1002/adfm.201600437</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/adfm.201600437" target="_blank" >10.1002/adfm.201600437</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Bulk Inclusions of Pyridazine-Based Molecular Rotors in Tris(o-phenylenedioxy)cyclotriphosphazene (TPP)

Popis výsledku v původním jazyce

A new class of rod-shaped strongly dipolar molecular rotors for insertion into channels of hexagonal tris(o-phenylenedioxy)cyclotriphosphazene (TPP) has been examined. Seven different 3,6-disubstituted pyridazines and one singly 3-substituted system have been prepared and studied by solid-state nuclear magnetic resonance (NMR), X-ray powder diffraction, and dielectric spectroscopy. NMR and X-ray diffraction both show that all but one of these molecular rotors form hexagonal bulk inclusion compounds with TPP. In-plane lattice parameters for the hexagonal phases increase with the size of the end group, which also controls the energy barriers for rotation of the pyridazine dipole. The barriers range from approximate to 4 kcal mol(-1) for small or flexible end groups to less than 0.7 kcal mol(-1) for 3-methylbicyclo[1.1.1]pent-1-yl end groups after annealing to 235 degrees C, and an interpretation of these differences is offered. Computer modeling of the relaxed TPP channels followed by density functional calculation of the environment for one of the rotors provides quantitative agreement with the observed barrier. The systems with the lowest rotational barriers show signs of collective behavior, discussed in terms of antiferroelectric intrachannel and ferroelectric interchannel dipole-dipole interactions. A Curie temperature of 22 K is deduced for 3,6-diadamant-1-ylpyridazine, but no ordered dielectric phases are found. Conclusions have been drawn for improved rotor design.

Název v anglickém jazyce

Bulk Inclusions of Pyridazine-Based Molecular Rotors in Tris(o-phenylenedioxy)cyclotriphosphazene (TPP)

Popis výsledku anglicky

A new class of rod-shaped strongly dipolar molecular rotors for insertion into channels of hexagonal tris(o-phenylenedioxy)cyclotriphosphazene (TPP) has been examined. Seven different 3,6-disubstituted pyridazines and one singly 3-substituted system have been prepared and studied by solid-state nuclear magnetic resonance (NMR), X-ray powder diffraction, and dielectric spectroscopy. NMR and X-ray diffraction both show that all but one of these molecular rotors form hexagonal bulk inclusion compounds with TPP. In-plane lattice parameters for the hexagonal phases increase with the size of the end group, which also controls the energy barriers for rotation of the pyridazine dipole. The barriers range from approximate to 4 kcal mol(-1) for small or flexible end groups to less than 0.7 kcal mol(-1) for 3-methylbicyclo[1.1.1]pent-1-yl end groups after annealing to 235 degrees C, and an interpretation of these differences is offered. Computer modeling of the relaxed TPP channels followed by density functional calculation of the environment for one of the rotors provides quantitative agreement with the observed barrier. The systems with the lowest rotational barriers show signs of collective behavior, discussed in terms of antiferroelectric intrachannel and ferroelectric interchannel dipole-dipole interactions. A Curie temperature of 22 K is deduced for 3,6-diadamant-1-ylpyridazine, but no ordered dielectric phases are found. Conclusions have been drawn for improved rotor design.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CC - Organická chemie

OECD FORD obor

—

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Advanced Functional Materials

ISSN

1616-301X

e-ISSN

—

Svazek periodika

26

Číslo periodika v rámci svazku

31

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

15

Strana od-do

5718-5732

Kód UT WoS článku

000383568300013

EID výsledku v databázi Scopus

2-s2.0-84971613803