1 Supporting information for: Intramolecular Hydrogen Bonding Stabilizes the Nuclearity of Complexes. A comparative study based on the H-carborane and Me- carborane framework. Mònica Fontanet, [a] Montserrat Rodríguez, [a] Xavier Fontrodona, [a] Isabel Romero,* [a] Clara Viñas, [b] and Francesc Teixidor,* , [b] a Departament de Química and Serveis Tècnics de Recerca, Universitat de Girona, Campus de Montilivi, E-17071 Girona, Spain. b Institut de Ciencia de Materials de Barcelona, ICMAB-CSIC, Campus UAB, E-08193 Bellaterra, Spain. Table S1. Crystal Data for X-ray structures of 1-5. Table S2. Crystal Data for X-ray structures of 2’and 4’. Table S3. Selected bond lengths (Å) and angles (°) for complexes 2’ and 4’. Table S4. Comparison of the structural parameters in Cu(II) dinuclear paddle-wheel and Cu(II) mononuclear carboranylcarboxylate complexes of the ligands 1-CO 2 H-2-H-1,2-closo-C 2 B 10 H 10 and 1- CO 2 H-2-CH 3 -1,2-closo-C 2 B 10 H 10 . Table S5. Selected hydrogen bonding distances (Å) for complexes 1- 5. Figure S1. Cyclic voltammetry recorded for complexes 2-5 in acetonitrile Figure S2. DPV images for complexes 3-5 at potential range from -0.6 to -0.1 in acetonitrile (0.1 M TBAH) with pulse amplitude of 0.05 V, pulse width of 0.05 s, sampling width of 0.02 s and pulse period of 0.5 s. Figure S3. NMR spectra of the compounds 1, 2/2’, 3, 4/4’, 5 and LH. The deconvolution of the 11 B NMR spectrum of compound 1 is also reported. Figure S4. Comparison of a) 1 H-NMR, b) 1 H{ 11 B}-NMR of compound 3 in chloroform at 298K (purple) and in acetone at 260K (black). Electronic Supplementary Material (ESI) for Dalton Transactions. This journal is © The Royal Society of Chemistry 2015