Ionic liquids from cationic palladium(ii) chelate complexes: preparation, thermal properties, and crystal structuresElectronic supplementary information (ESI) available: DSC traces of 1-3 (Fig. S1) and ORTEP drawings of the molecular structures of 1-3 (Fig. S2 and S3). CCDC 975545 (1), 975546 (2), and 976918 (3). For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4dt00192c

Metal-containing ionic liquids comprising cationic Pd II chelate complexes and the bis(trifluoromethanesulfonyl)amide (Tf 2 N) anion were prepared: [Pd(acac)(Me 4 en)]Tf 2 N ( 1 ), [Pd(acac)(BuMe 3 en)]Tf 2 N ( 2 ), and [Pd(C 8 -acac)(Me 4 en)]Tf 2 N ( 3 ) (acac = 2,4-pentanedionate, C 8 -acac = 3-octyl-2,4-pentanedionate, Me 4 en = N , N , N ′, N ′-tetramethylethylenediamine, BuMe 3 en = N -butyl- N , N ′, N ′-trimethylethylenediamine). These salts were yellow solids with melting points of 85.2 °C, 71.1 °C, and 62.3 °C, respectively. During cooling from the liquid state, complex 1 exhibited crystallization, whereas 2 and 3 exhibited only glass transitions at approximately −40 °C. X-ray structure determination revealed that the cations in 1 and 3 form dimer-like arrangements and that there were no direct contacts between the charged moieties of the cations and anions in the solid state. Ionic liquids containing cationic palladium chelate complexes were prepared. These salts were yellow crystals with melting points of 60-90 °C. X-ray structure determination revealed the tendency of dimer-like arrangement of the cations in the solid state.