Issue 40, 2020

Structure, polymorphism and luminescence of cyanate iodides MI(OCN) (M = Ba, Eu, and Sr)

Abstract

A series of new compounds MI(OCN) were prepared from the mixtures of MI2 and K(OCN) (M = Sr, Eu or Ba) by solid-state reactions that were controlled by differential scanning calorimetry (DSC) and differential thermal analysis (DTA) techniques. The presence of two phases is highlighted for BaI(OCN) which crystallizes in the Pnma (α-BaI(OCN)) and Cmcm (β-BaI(OCN)) space groups. The SrI(OCN), EuI(OCN) and β-BaI(OCN) compounds crystallize in the same orthorhombic Cmcm space group and the structure consists of a layered arrangement of [M2I2]2+ blocks separated by single layers of cyanate ions that are found to be related to the Sillén-type structure. The polymorphism of BaI(OCN) was also observed by analyzing the infrared (IR) spectra. This analysis showed for β-BaI(OCN) splitting bands, which were ascribed to the presence of more than one resonant cyanate form that can be induced by the dynamical disorder of OCN units. In contrast, the α-BaI(OCN) vibration modes suppose the existence of one cyanate form that adopts a defined orientation. The SrI(OCN) and BaI(OCN) compounds were doped with Eu2+. The luminescence spectra recorded under excitation at 340 and 350 nm revealed a blue emission of Eu2+ at 431 nm for the β-BaI(OCN) and SrI(OCN) phases and at 427 nm for the α-BaI(OCN) phase that was ascribed to the 4f65d18S7/2 (4f7) transition.

Graphical abstract: Structure, polymorphism and luminescence of cyanate iodides MI(OCN) (M = Ba, Eu, and Sr)

Supplementary files

Article information

Article type
Paper
Submitted
15 Jun 2020
Accepted
14 Sep 2020
First published
14 Sep 2020

Dalton Trans., 2020,49, 14133-14139

Structure, polymorphism and luminescence of cyanate iodides MI(OCN) (M = Ba, Eu, and Sr)

A. Siai, L. Hämmerle, M. Ströbele, D. Enseling, T. Jüstel and H. Meyer, Dalton Trans., 2020, 49, 14133 DOI: 10.1039/D0DT02126A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements