Carbon dioxide uptake by [Cu(bpca)] + : synthesis, crystal structure, and magnetic properties of {[Na(H 2 O) 2 ][Cu 2 (bpca) 2 (CO 3 )(HCO 3 )]} n [Hbpca = bis(2-pyridylcarbonyl)amide]

• Published in: New journal of chemistry Vol. 47; no. 3; pp. 1066 - 1075
• Main Authors: da Silva, Rafaela M. R., Rosa, Iara M. L., Oliveira, Willian X. C., Alves, Odivaldo C., Santos, Evelyn C. S., Garcia, Flávio, Silva Junior, Henrique C., Ferreira, Glaucio B., Guedes, Guilherme P., do Pim, Walace D., Julve, Miguel, Marinho, Maria Vanda
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 16.01.2023
• Subjects: Basal plane; Bicarbonates; Carbon dioxide; Coordination polymers; Copper; Cryomagnetic properties; Crystal structure; Crystallography; Density functional theory; Electronic structure; Ferromagnetism; Ligands; Magnetic properties; Nitrogen atoms; Oxygen atoms; Sodium; Structural analysis; Thermodynamic properties; Topology; Vapor phases; Water chemistry
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/D2NJ05268G

Herein we report on the preparation, spectroscopic and thermal characterization, structural study, and magnetic investigation of a new heterobimetallic coordination polymer (CP) of formula {[Na(H 2 O) 2 ][Cu 2 (bpca) 2 (CO 3 )(HCO 3 )]} n (1) [Hbpca = bis(2-pyridylcarbonyl)amide], which was isolated through the fixation of aerial carbon dioxide by the preformed [Cu(bpca)] + complex in basic water/DMSO solvent mixtures. Compound 1 is made up of neutral heterobimetallic zigzag chains growing parallel to the crystallographic c axis where carbonate, bicarbonate, and bpca anions act as bridges with regular alternation of a pair of [Cu(bpca)] + units and one [Na(H 2 O) 2 ] + fragment. The two crystallographically independent copper( ii ) ions (Cu1 and Cu2) are five-coordinate in somewhat distorted square pyramidal surroundings with three nitrogen atoms from the bpca ligand and either one bicarbonate-oxygen (Cu1) or a carbonate-oxygen (Cu2) in the basal plane and a shared carbonate-oxygen atom (Cu1 and Cu2) in the apical position. Each sodium( i ) ion is also five-coordinate in a distorted trigonal bipyramidal environment, with two oxygen atoms from a bpca ligand and a water molecule building the trigonal plane and a bicarbonate-oxygen and another water molecule in the axial sites. The intrachain copper–copper separation across the bridging carbonate is 4.109(1) Å. The cryomagnetic study of 1 reveals the occurrence of a weak ferromagnetic interaction between the copper(II) ions through the bridging carbonate [ J = +0.17(4) cm −1 , the spin Hamiltonian being defined as H = −J S Cu1 · S Cu2 ]. Density functional theory (DFT) calculations on the [{Cu(bpca)} 2 (μ-CO 3 )] fragment of 1 in the gas phase and solid state were used to estimate the magnetic coupling constant ( J = +0.42 cm −1 ) and to describe the electronic structure and magnetic topology of the system.