Discrete {GdIII4M} (M = GdIII or CoII) pentanuclear complexes: a new class of metal-organophosphate molecular coolersElectronic supplementary information (ESI) available: Experimental and computational details as a PDF; CIF for 1 (CCDC 1030609) and 2 (CCDC 1030610). CCDC 1030609 and 1030610. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4dt03655g

The first examples of homo- and hetero-polymetallic organophosphates of gadolinium are reported. Magnetic measurements reveal a higher magnetic entropy change for the isotropic {Gd III 5 } complex (25.8 J kg −1 K −1 ) as compared to the heterometallic {Gd III 4 Co II } complex (20.3 J kg −1 K −1 ), which is attributable to a change in magnetic coupling as estimated from DFT calculations. A higher magnetic entropy change is observed for the homometallic {Gd III 5 } complex (25.8 J kg −1 K −1 ) as compared to the heterometallic {Gd III 4 Co II } complex (20.3 J kg −1 K −1 ).