Syntheses and Crystal Structure of Erbium(Ⅲ) Coordination Polymers with Two Flexible Double Betaine Ligands

1INTR0DUCTI0NLanthanidecarboxylatecomplexeshavebeenwidelystudiedt1iandm0starefoundtoexhibitavarietyofdimericorinfinitechainstructures.Recentstudiesinourlaboratoryhavedem0nstratedthattheprototypetertiaryaminebetaine(Me,N CHzC0z-)anditsderivativesareusefulinthegenerationoflanthanidecarb0xylate-likecomplexeswithnewstructuralfeaturesduetotheiroverallchargeneutralityandpossibleinclusionofvariouskindsofcounteranionsinthestructuret2~4i.Thelan-thanidecomplexesisolatedsofarhavebeenfoundtobemononu…

Syntheses and Crystal Structure of Erbium(Ⅲ) Coordination Polymers with Two Flexible Double Betaine Ligands

Two new polymeric erbium(Ⅲ) complexes of two flexible double betaine ligands have been synthesized and characterized by X-ray analysis. In {[Er(L1)(H2O)4)Cl3 H2O}n (1) (L1 = 4, 4' -trimethylenedipyridinio-N, N'-diacetate ), the erbium(Ⅲ) ions form a two-dimensional metal carboxylate layer in which each pair of Er(Ⅲ) atoms is bridged by two syn-anti μ-carboxylato-o,o' groups, Adjacent layers arecross-linked through hydrogen bonds among aqua ligands, lattice water molecules andchloride ions to form a three-dimensional network. Complex l, C17 H28 N2 O9 ErC13 (Mr =676.0) is monoclinic, space group C2, with a= 27. 408(4), b= 9. 645 (3), c= 9. 423(2) A, p=1loo. 85(1)', V=2446. 2(9) A', Z=4, D=l. 836 g/cm', F(OOO) =1332, μ(MoKa) = 38.06 cm-1, R=0. 048 for 2451 reflections with I>2σ(I). { [Er(L2 ) (H2O)4]Cl3. 5H2O}. (2) (L2=1, 3-bis (pyridinio-4-carboxylato) propane) comprises lanthanide carboxylate chains built from centrosymmetric dimeric units crosslinked by a pair of L2 ligands, discrete anions and lattice water molecules. In the dimeric unit of complex 2, each pair of metal ions is bridged by four syn-syn μ-carboxylatoO, O' groups that are oriented nearly perpendicular to each other about the metal-metalaxis. The metal carboxylate chains of complex 2 are further cross-linked by hydrogenbonds to form a three-dimensional network. Complex 2, C15 H32 N2O13 ErCl3 (Mr=722.0) belongs to the monoclinic space group C2/m with a=16. 564 (3), b=15. 839(3), c=11. 792(4) , β=122. 27(1)°, V=2616(1), Z=4, Dc=1.833 g/cm3,F(000) =1436, μ (MoKa) = 35. 75 cm-1, R =0.043 for 2436 observed reflectionswithI>2σ(I).