A two-dimensional yttrium phthalate coordination polymer, [Y4(H2O)2(C8H4O4)6]¥, exhibiting different coordination geometries

A hydrothermal reaction of a mixture of Y(NO3)3, 1,2-benzenedicarboxylic acid (1,2-BDC) and NaOH gives rise to a new yttrium phthalate coordination polymer, [Y4(H2O)2(C8H4O4)6].., I. The Y ions in I are present in four different coordination environments with respect to the oxygen atoms (CN6 = octahedral, CN7 = pentagonal bipyramid, CN8 = dodecahedron and CN9 = capped square antiprism). The oxygen atoms of the 1,2-BDC are fully deprotonated, and show variations in their connectivity with Y atoms. The Y atoms themselves are connected through their vertices forming infinite Y–O–Y one-dimensional chains. The Y–O–Y chains are cross-linked by the 1,2-BDC anions forming a corrugated layer structure. The layers are supported by favourable p¼p interactions between the benzene rings of the 1,2-BDC anions. The variations in the coordination environment of the Y atoms and the presence of Y–O–Y interactions along with the favourable pp interactions between the benzene rings from different layers are noteworthy structural features. Crystal data: triclinic, space group = P–1 (no. 2), a = 12,6669 (2), b = 13,8538 (2), c = 16,0289 Å, alpha= 75,200 (1),beta= 69,012 (1),gamma= 65,529 (1), V = 2371,28 (7) Å3, Dcalc = 1,922 g cm–1, m(MoKa) = 4,943 mm–1. A total of 9745 reflections collected and merged to give 6566 unique reflections (Rint = 0,0292) of which 5252 with I > 2s(I) were considered to be observed. Final R2 = 0,0339, wR2 = 0,0724 and S = 1,036 were obtained for 704 parameters.