RARE-EARTH PHENYLTELLUROLATES - 1D COORDINATION POLYMERS

THF coordination complexes of Eu(TePh)(2) and Yb(TePh)(2) crystallize as one-dimensional polymers. Transmetalation, rather than salt elimina tion, is the superior synthetic approach to these materials. Addition of 3 equiv of NaTeC6H5 to a solution of EuCl3 in THF gives crystals of the bimetallic one-dimensional coordination polymer [(THF)(3)Eu(TeC6H 5)(2)NaTePh](infinity) (1). If the reaction product is dissolved in py ridine, crystalline (pyridine)(5)Eu(TeC6H5)(2) is isolated. Recrystall ization of (pyridine)(5)Eu(TeC6H5)(2) from THF gives the one-dimension al polymer [(THF)(2)Eu(TeC6H5)(2)](infinity) (2), which can also be pr epared by the transmetalation reaction between Hg(TePh)(2) and Eu in T HF. The analogous Yb salt elimination reactions do not give crystallin e material, but the THF complex of Yb(TePh)(2) can be prepared by tran smetalation using Hg(TePh)(2), and crystallizes as [(THF)(2)Yb(TeC6H5) (2.)(1)/2THF](infinity) (3). All three coordination polymers (1-3) wer e characterized by low-temperature single-crystal X-ray diffraction. T he structure of 1 contains pairs of divalent europium ions bridged by a pair of mu(3)-PhTe ligands that are also coordinated to one Na. The Europium coordination sphere also includes three THF ligands, one mu(3 )-PhTe ligand that bridges one of the Eu and two Na ions that separate the pair of europium atoms from the next pair of Eu(II) ions, and one mu(2)-PhTe ligand that bridges one Eu and Na. The structure of 2 cont ains a one-dimensional array of octahedral metal ions bound to cis-THF ligands and a pair of two bridging mu(2)-phenyltellurolato ligands. P olymer 3 also contains octahedral metal ions with cis-THF, but in this structure the metal ions are connected to adjacent metals by an alter nating number (1-3-1-3) of mu(2)-phenyltellurolates. Crystal data (Mo K alpha, -100 degrees C): 1, space group <P(1)over bar>, a = 9.800(3) Angstrom, b = 13.453(8) Angstrom, c = 14.019(4) Angstrom, alpha = 104. 81(4)degrees, beta = 103.50(2)degrees, gamma = 100.50(2)degrees; 2, sp ace group <P(1)over bar>, a = 8.533(4) Angstrom, b = 10.285 Angstrom, c = 13.490(4) Angstrom, alpha = 71.57(2)degrees, beta = 88.69(3)degree s, gamma = 85.32(3)degrees;3, space group P2(1)/c, a = 13.805(5) Angst rom, b = 19.149(5) Angstrom, c = 18.115(8) Angstrom, beta = 100.30(3)d egrees.