Multistimuli Response Micro‐ and Nanolayers of a Coordination Polymer Based on Cu2I2 Chains Linked by 2‐Aminopyrazine. Issue 33 (10th July 2017)

• Record Type: Journal Article
• Authors: Conesa‐Egea, J.; Gallardo‐Martínez, J.; Delgado, S.; Martínez, J. I.; Gonzalez‐Platas, J.; Fernández‐Moreira, V.; Rodríguez‐Mendoza, U. R.; Ocón, P.; Zamora, F.; Amo‐Ochoa, P.
• Is Part Of: Small. Volume 13:Issue 33(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-07-10
• Subjects: coordination polymers -- multifunctional materials -- nanomaterials -- stimuli response materials; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201700965
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract : A nonporous laminar coordination polymer of formula [Cu2 I2 (2‐aminopyrazine)] n is prepared by direct reaction between CuI and 2‐aminopyrazine, two industrially available building blocks. The fine tuning of the reaction conditions allows obtaining [Cu2 I2 (2‐aminopyrazine)] n in micrometric and nanometric sizes with same structure and composition. Interestingly, both materials show similar reversible thermo‐ and pressure‐luminescent response as well as reversible electrical response to volatile organic solvents such as acetic acid. X‐ray diffraction studies under different conditions, temperatures and pressures, in combination with theoretical calculations allow rationalizing the physical properties of this compound and its changes under physical stimuli. Thus, the emission dramatically increases when lowering the temperature, while an enhancement of the pressure produces a decrease in the emission intensity. These observations emerge as a direct consequence of the high structural flexibility of the Cu2 I2 chains which undergo a contraction in CuCu distances as far as temperature decreases or pressure increases. However, the strong structural changes observed under high pressure lead to an unexpected effect that produces a less effective CuCu orbital overlapping that justifies the decrease in the intensity emission. This work shows the high potential of materials based on Cu2 I2 chains for new applications. Abstract : Lamellar semiconducting multistimuli coordination polymer based on Cu(I)‐I‐2‐aminopyrazine chains is isolated in micro‐ and nanometric dimensions. The materials present high emission when temperature decreases and loses this emission with pressure, as a consequence of a shortening in CuCu distances. This apparent dilemma is rationalized by the use of theoretical calculations that demonstrate an ineffective overlapping of copper dz 2 orbitals as pressure increases.