C68H60Co2N8O18, triclinic, P1 (no. 2), a = 7.299(5) A, b = 13.865(5) A, c = 15.840(5) A, α = 83.889(5)°, * = 83.626(5)°, γ = 78.785(5)°, V = 1556.7 A, Z = 1, Rgt(F) = 0.045, wRref(F) = 0.096, T = 293 K. Source of material A mixture of biphenylethene-4,4'-dicarboxylatic acid (H2bpea, 1.mmol), dipyrido[3,2-a:2',3'-c]phenazine (dppz, 0.5 mmol), and CoCl2.·.6H2O (1 mmol) was suspended in a mixed solution of deionized water (12 ml) and sealed in a 20 ml Teflon-lined autoclave. Upon heating at 140 °C for three days, the autoclave was slowly cooled to room temperature. Red crystals were collected, washed with deionized water and dried. Experimental details H atoms on C atoms were generated geometrically and refined as riding atoms with d(C—H) = 0.93 A and Uiso(H) = 1.2 Ueq(C). TheH atoms of thewatermolecules (O1W,O2WandO3W)were found in a difference Fourier map and refined, but the H atoms of water molecules (O4W and O5W) were not located. Discussion The coordination polymers based on a N-donor chelating ligand, such as 1,10-phenanthroline (phen), have been widely studied. However, far less attention has been payed to the derivatives of phen. Dipyrido[3,2-a:2',3'-c]phenazine (dppz) as an important phen derivative possesses fruitful aromatic systems and may be a good candidate for the construction of metal-organic supramolecular architectures [1]. Here, we selected biphenylethene-4,4'dicarboxylatic acid (H2bpea) as a organic linker and dppz as a Ndonor chelating ligand, forming a new coordination polymer, [Co2(H2O)4(bpea)(dppz)2]2.·.bpea.·.6H2O. In the title crystal structure eachCo(II) is six-coordinated in a distorted octahedral environment and is surrounded by two carboxylate oxygen atoms from one bpea anion, two water molecules and two nitrogen atoms from one dppz ligand. The average Co—O and Co—N distances are comparable to the literature data. Two neighbouringCo(II) atoms are linked by the same bpea ligand to form a dimer. Slipped --stack arrangements between dppz and bpea ligands were observed (centroid-to-centroid distance of 3.69(4) A, vertical face-to-face distance of 3.52(3) A, and dihedral angle of 1.07(4)°), which extends the dimers into a supramolecular structure. 528 Z. Kristallogr. NCS 224 (2009) 528-530 / DOI 10.1524/ncrs.2009.0231 © by Oldenbourg Wissenschaftsverlag, Munchen Crystal: red block, size 0.19 × 0.28 × 0.33 mm Wavelength: Mo K+ radiation (0.71073 A) .: 6.15 cm−1 Diffractometer, scan mode: Bruker APEX CCD, #/% 2,max: 52.82° N(hkl)measured, N(hkl)unique: 12364, 6303 Criterion for Iobs, N(hkl)gt: Iobs > 2 )(Iobs), 3566 N(param)refined: 455 Programs: SHELXS-97 [2], SHELXL-97 [3], SHELXTL [4] Table 1. Data collection and handling.