Surface-Induced Phase of Tyrian Purple (6,6 '-Dibromoindigo): Thin Film Formation and Stability

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10325219" target="_blank" >RIV/00216208:11320/16:10325219 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1021/acs.cgd.6b00104" target="_blank" >http://dx.doi.org/10.1021/acs.cgd.6b00104</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.cgd.6b00104" target="_blank" >10.1021/acs.cgd.6b00104</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Surface-Induced Phase of Tyrian Purple (6,6 '-Dibromoindigo): Thin Film Formation and Stability

Popis výsledku v původním jazyce

The appearance of surface-induced phases of molecular crystals is a frequently observed phenomenon in organic electronics. However, despite their fundamental importance, the origin of such phases is not yet fully resolved. The organic molecule 6,6'-dibromoindigo (Tyrian purple) forms two polymorphs within thin films. At growth temperatures of 150 oC, the well-known bulk structure forms, while at a substrate temperature of 50 oC, a surface-induced phase is observed instead. In the present work, the crystal structure of the surface-induced polymorph is solved by a combined experimental and theoretical approach using grazing incidence X-ray diffraction and molecular dynamics simulations. A comparison of both phases reveals that π-π stacking and hydrogen bonds are common motifs for the intermolecular packing. In-situ temperature studies reveal a phase transition from the surface-induced phase to the bulk phase at a temperature of 210 oC; the irreversibility of the transition indicates that the surface-induced phase is metastable. The crystallization behavior is investigated ex-situ starting from the sub-monolayer regime up to a nominal thickness of 9 nm using two different silicon oxide surfaces; island formation is observed together with a slight variation of the crystal structure. This work shows that surface-induced phases not only appear for compounds with weak, isotropic van der Waals bonds, but also for molecules exhibiting strong and highly directional hydrogen bonds.

Název v anglickém jazyce

Surface-Induced Phase of Tyrian Purple (6,6 '-Dibromoindigo): Thin Film Formation and Stability

Popis výsledku anglicky

The appearance of surface-induced phases of molecular crystals is a frequently observed phenomenon in organic electronics. However, despite their fundamental importance, the origin of such phases is not yet fully resolved. The organic molecule 6,6'-dibromoindigo (Tyrian purple) forms two polymorphs within thin films. At growth temperatures of 150 oC, the well-known bulk structure forms, while at a substrate temperature of 50 oC, a surface-induced phase is observed instead. In the present work, the crystal structure of the surface-induced polymorph is solved by a combined experimental and theoretical approach using grazing incidence X-ray diffraction and molecular dynamics simulations. A comparison of both phases reveals that π-π stacking and hydrogen bonds are common motifs for the intermolecular packing. In-situ temperature studies reveal a phase transition from the surface-induced phase to the bulk phase at a temperature of 210 oC; the irreversibility of the transition indicates that the surface-induced phase is metastable. The crystallization behavior is investigated ex-situ starting from the sub-monolayer regime up to a nominal thickness of 9 nm using two different silicon oxide surfaces; island formation is observed together with a slight variation of the crystal structure. This work shows that surface-induced phases not only appear for compounds with weak, isotropic van der Waals bonds, but also for molecules exhibiting strong and highly directional hydrogen bonds.

Druh

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

CEP obor

BM - Fyzika pevných látek a magnetismus

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

Crystal Growth and Design

ISSN

1528-7483

e-ISSN

—

Svazek periodika

16

Číslo periodika v rámci svazku

7

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

9

Strana od-do

3647-3655

Kód UT WoS článku

000379456700015

EID výsledku v databázi Scopus

2-s2.0-84978945219