1 Supporting Information for the manuscript From pink to blue and back to pink again: changing the Co(II) ligation in a two-dimensional coordination network upon desolvation D. Chisca, a L. Croitor, a E. B. Coropceanu, b O. Petuhov, b S. G. Baca, a K. Krämer, c S.-X. Liu, c S. Decurtins, c H. J. Rivera-Jacquez, d A. E. Masunov, d,e M. S. Fonari a* a Institute of Applied Physics Academy of Sciences of R. Moldova, Academy str., 5 MD2028, Chisinau, Moldova; Tel.: + 373 22 738154; fax:+ 373 22 725887, E-mail: fonari.xray@phys.asm.md; b Institute of Chemistry Academy of Sciences of R. Moldova, Academy str., 3 MD2028, Chisinau, Moldova; c Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, 3012 Bern, Switzerland; d NanoScience Technology Center, 12424 Research Parkway Suite 400 Orlando, FL 32826 and Department of Chemistry, Department of Physics, and Florida Solar Energy Center, University of Central Florida, Orlando, Florida 32826, United States. e Department of Condensed Matter Physics, National Research Nuclear University MEPhI, Kashirskoye shosse 31, Moscow, 115409, Russia. EXPERIMENTAL SECTION Materials and general methods All reagents and solvents were obtained from commercial sources and were used without further purification. Elemental analysis was performed on an Elementar Analysensysteme GmbH Vario El III elemental analyzer. The IR spectrum for 1 was recorded in a FT IR Spectrum-100 Perkin Elmer spectrometer in the range of 400 – 4000 cm 1 . The thermogravimetric analysis (TGA) was carried out with a Derivatograph Q-1500 thermal analyzer in an air flow at a heating rate of 5 °C/min in the temperature range of 25–1000 °C. The nitrogen adsorption-desorption isotherm has been measured using an Autosorb-1MP device. Magnetic susceptibility data were recorded using a Quantum design MPMS-5XL SQUID magnetometer in the temperature range 1.9 – 300 K and at a field of 1 kG. Experimental data were corrected for sample holder and diamagnetic contributions (-0.45 × molecular weight × 10 6 cm 3 mol 1 ). The X-ray powder diffraction data for samples 1, dry_1, and dry_1s were collected at room temperature on a DRON-UM, 30/30 kW/mA, 2x10 2 imp/sec, diffractometer using FeK(av) radiation (= 1.93604 Å). Single crystal X-ray crystallography The crystallographic data for 1, dry_1, and dry_1s were collected at a room temperature on a „Xcalibur Oxford Diffraction” diffractometer equipped with a CCD area detector and a graphite monochromator utilizing MoK radiation, and were also recollected for 1 at 100 K on a 'SuperNova, Single source at offset, Eos', diffractometer equipped with a CCD area detector and a graphite monochromator utilizing MoK radiation. Final unit cell dimensions were obtained and refined on an entire data set. All calculations to solve the structures and to refine the proposed models were carried out with the programs SHELXS-2014 and SHELXL-2014. 1 The structures 1 and dry_1 were solved by direct methods and refined by full-matrix least-squares methods on F 2 by using the SHELXL- 2014 program package. Compound 1 is stable in ambient conditions for a long time that allowed recollecting the single crystal X-ray data for this sample at 100 K. The data recollected for 1 at LT did not principally Electronic Supplementary Material (ESI) for CrystEngComm. This journal is © The Royal Society of Chemistry 2015