title: Gadolinium sulfate modified by formate to obtain optimized magneto-caloric effect.
abstract: Three new Gd(III) based coordination polymers [Gd2(C2H6SO)(SO4)3(H2O)2]n (1), {[Gd4(HCOO)2(SO4)5(H2O)6]·H2O}n (2), and [Gd(HCOO)(SO4)(H2O)]n (3) were obtained by modifying gadolinium sulfate. With the gradual increase of the volume ratio of HCOOH and DMSO in synthesis, the formate anions begin to coordinate with metal centers; this results in the coordination numbers of sulfate anion increasing and the contents of water and DMSO molecules decreasing in target complexes. Accordingly, spin densities both per mass and per volume were enhanced step by step, which are beneficial for the magneto-caloric effect (MCE). Magnetic studies reveal that with the more formate anions present, the larger the negative value of magnetic entropy change (-ΔSm) is. Complex 3 exhibits the largest -ΔSm = 49.91 J kg(-1) K(-1) (189.51 mJ cm(-3) K(-1)) for T = 2 K and ΔH = 7 T among three new complexes.
authors.affiliation: †School of Chemistry and Chemical Engineering, Tianjin University of Technology, No. 391 Binshui Xilu Road, Tianjin 300384, P. R. China.
authors.forename: Long-Yang
authors.initials: LY
authors.lastname: Xu
authors.affiliation: †School of Chemistry and Chemical Engineering, Tianjin University of Technology, No. 391 Binshui Xilu Road, Tianjin 300384, P. R. China.|§School of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, P. R. China.
authors.forename: Jiong-Peng
authors.initials: JP
authors.lastname: Zhao
authors.affiliation: †School of Chemistry and Chemical Engineering, Tianjin University of Technology, No. 391 Binshui Xilu Road, Tianjin 300384, P. R. China.
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.affiliation: †School of Chemistry and Chemical Engineering, Tianjin University of Technology, No. 391 Binshui Xilu Road, Tianjin 300384, P. R. China.
authors.forename: Fu-Chen
authors.initials: FC
authors.lastname: Liu