Key indicators: single-crystal X-ray study; T = 180 K; mean (C-C) = 0.003 Å; disorder in main residue; R factor = 0.039; wR factor = 0.108; data-to-parameter ratio = 14.5.In the title compound, [Zn(C 44 H 28 N 4 )]ÁC 12 H 24 O 6 , the Zn II ion lies on an inversion center and the asymmetric unit contains one half of a Zn(TPP) complex (TPP = 5,10,15,20-tetraphenylporphyrin dianion) and one half of a centrosymmetric 18-crown-6 molecule. The Zn(TPP) complex exhibits a nearly planar conformation of the porphyrin core [maximum deviation = 0.106 (2) Å ] with an average Zn-N distance of 2.047 (2) Å . The title compound is considered as a onedimensional polymer along [010], in which the Zn(TPP) moiety is linked to the closest O atoms of two symmetryrelated 18-crown-6 molecules with a Zn-O distance of 2.582 (1) Å , completing a distorted octahedral coordination environment of the metal ion. The chains are mainly sustained by weak C-HÁ Á Á interactions. An ethylene group of the 18-crown-6 molecule is disordered over three sites with occupancies of 0.50, 0.25 and 0.25. Table 1 Hydrogen-bond geometry (Å , ). Related literatureCg1, Cg2 and Cg3 are the centroids of the N1/C1-C4, N2/C6-C9 and C11-C16 rings, respectively. metal-organic compounds m444 Denden et al.