Feature article Synthesis and characterization of Cu(I) and Zn(II) complexes with new sulfur-bearing isoxazole- or pyrazole-based ligands Neudo Urdaneta a , Vanessa R. Landaeta a, ⁎, Rafael E. Rodríguez-Lugo b,1 , Carlos Díaz a , Gustavo Santiso-Quinones b , Jairo Quiroga c , Braulio Insuasty c a Departamento de Química, Universidad Simón Bolívar, Valle de Sartenejas, Baruta, Apartado 89000, Caracas 1080A, Venezuela b Department of Chemistry and Applied Biosciences, ETH, Hönggerberg, 8093 Zurich, Switzerland c Grupo de Investigación de Compuestos Heterocíclicos, Departamento de Química, Universidad del Valle, A.A. 25360 Cali, Colombia abstract article info Article history: Received 18 June 2014 Received in revised form 12 December 2014 Accepted 3 March 2015 Available online 5 March 2015 Keywords: Isoxazole-based ligand Pyrazole-based ligand Luminescence Zn(II) complexes Cu(I) complexes 1D coordination polymer The synthesis of the new ligands 6-(5-methyl-1,2-oxazol-3-yl)-2,3-dihydro-5H-[1,4] dithiino[2,3-c]pyrrole- 5,7(6H)-dione (isox′) and 6-(3-methyl-1H-pyrazol-5-yl)-2,3-dihydro-5H-[1,4]dithiino[2,3-c]pyrrole-5,7(6H)- dione (pyraz′) and their coordination chemistry toward Cu(I) and Zn(II), was studied. The ligands and their complexes were characterized using a combination of either multinuclear NMR ( 1 H and 13 C{ 1 H}), HRMS, FTIR or Uv–Vis spectroscopy. The solid state structures of ligand isox′ and complexes [Cu(pyraz′) 2 ]OTf and [Zn(OOCCF 3 ) 2 (pyraz′) 2 ] were determined. Interestingly, isox′ presents a yellow luminescence in its free form. Additionally, the ability of isox′ to coordinate as an N–O bidentate ligand or as an N–S bridge between two copper centers, forming a coordination polymer, is studied. The solid state structure of this Cu(I)-isox′ 1D coordination polymer is also reported. © 2015 Elsevier B.V. All rights reserved. Contents Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Appendix A. Supplementary material . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Pyrazole or isoxazole-type ligands have been widely used in coordi- nation chemistry [1]. Transition metal complexes containing these types of ligands, and the investigation of their properties, have become an interesting research field since these are relevant in bioinorganic chemistry [2], catalysis [3] and materials with magnetic [4], optical (in search for luminescent sensors) [3a,5,6] or electrical properties [7]. The interest in pyrazole or isoxazole-based ligands resides in the fact that their chemical structure can be modified straightforwardly, affect- ing then their steric environment and the one of their metal complexes. Furthermore, the pyrazole ring can be easily incorporated into larger polydentate ligand structures, and some examples have been recently published for that matter [1e,5]. The 1,4-dithia-2,3-tetrahydrophthalimide group (substituent R shown in Fig. 1) is commonly found in compounds with biological activ- ity [8]. Bielenica et al. reported a series of aminoalkanol derivatives bearing the dithiatetrahydrophthalimide group and studied their antifungal and antibacterial properties [8a]. The group of Zentz synthesized a family of N-substituted dithiines and tested them as antimicrobial agents [8b]. Konecny et al. have prepared several N-substituted dithiatetrahydrophthalimides that showed low fungi- cidal and herbicidal activity [8c]. Fickentscher and co-workers inves- tigated the stereochemical properties and teratogenic activity of some tetrahydrophthalimides [8d]. The compound 3,6-dithia-4,5- tetrahydrophthalimide, structurally characterized by Fickentscher, has been found to cause embryotoxicity and teratogenicity in mice [8e]. To the best of our knowledge, only the Zn(II) azaphthalocyanine Inorganic Chemistry Communications 55 (2015) 43–47 ⁎ Corresponding author. E-mail addresses: urdanet@usb.ve (N. Urdaneta), vlandaeta@usb.ve (V.R. Landaeta). 1 Current address: Laboratorio de Química Bioinorgánica, Centro de Química, Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas 1020-A, Venezuela. http://dx.doi.org/10.1016/j.inoche.2015.03.007 1387-7003/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Inorganic Chemistry Communications journal homepage: www.elsevier.com/locate/inoche