Issue 14, 2018

Halogen bonds in 2,5-dihalopyridine-copper(ii) chloride complexes

Abstract

Ten coordination complexes obtained through a facile reaction between 2,5-dihalopyridines and copper(II) chloride (CuCl2) are characterized using single crystal X-ray diffraction. Two series of dihalopyridine complexes based on 2-chloro-5-X-pyridine and 2-bromo-5-X-pyridine (X = F, Cl, Br and I) were prepared to analyze the C–X2/X5⋯Cl–Cu halogen bonds (XB). The influence of X2- and X5-substituents on the respective interactions was examined by comparing them to the X2/X3⋯Cl–Cu XBs found in mono-substituted halopyridine complexes, (n-X-pyridine)2·CuCl2 (n = 2, 3 and X = Cl, Br and I). Varying the X5-halogens in (2,5-dihalopyridine)2·CuCl2, the C5–X5⋯Cl–Cu XBs follow the order F5 < Cl5 < Br5 < I5 for X2 = Cl and Cl5 < Br5 < I5 for X2 = Br. The C2–X2⋯Cl–Cu XB distances did not follow any particular trends, and are slightly longer compared to corresponding distances in (2-halopyridine)2·CuCl2 complexes due to the competition of X2 and X5-halogen based halogen bonds. The C3–X3⋯Cl–Cu contacts in (3-halopyridine)2·CuCl2 have RXB values > 1 and they cannot be considered as halogen bonds. This proves the polarization effect of X2- to X5- rather than X5- to X2-halogen, and the introduction of second halogen substituent in para-position to X5- triggers C2–X2⋯Cl–Cu and C5–X5⋯Cl–Cu XB interactions.

Graphical abstract: Halogen bonds in 2,5-dihalopyridine-copper(ii) chloride complexes

Supplementary files

Article information

Article type
Paper
Submitted
08 Feb 2018
Accepted
02 Mär 2018
First published
02 Mär 2018

CrystEngComm, 2018,20, 1954-1959

Halogen bonds in 2,5-dihalopyridine-copper(II) chloride complexes

R. Puttreddy, C. von Essen, A. Peuronen, M. Lahtinen and K. Rissanen, CrystEngComm, 2018, 20, 1954 DOI: 10.1039/C8CE00209F

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