catena-Poly[[silver(I)-μ-1,2-bis(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)ethane-κ2 N:N′] perchlorate hemihydrate]

In the title coordination polymer, {[Ag(C12H20N2O2)]ClO4·0.5H2O}n, the AgI cation is coordinated by two N atoms from two 1,2-bis(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)ethane (L) ligands in a nearly linear geometry [N—Ag—N = 171.07 (8)°]. The L ligand bridges adjacent Ag+ cations, forming a polymeric chain running along the c axis. The lattice water molecule is situated on a twofold rotation axis, and links to the perchlorate anion via an O—H⋯O hydrogen bond. The long Ag⋯O separation of 3.200 (4) Å indicates a weak interaction between the perchlorate anion and the AgI cation. Weak C—H⋯O hydrogen bonding occurs between the chain and the lattice water molecule and between the chain and perchlorate anions. Both five-membered rings of the L ligand display envelope conformations; in one five-membered ring, the flap C atom is disordered on opposite sides of the ring with occupancies of 0.65 and 0.35.

In the title coordination polymer, {[Ag (C 12 H 20 N 2 O 2 )]ClO 4 Á-0.5H 2 O} n , the Ag I cation is coordinated by two N atoms from two 1,2-bis(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)ethane (L) ligands in a nearly linear geometry  ]. The L ligand bridges adjacent Ag + cations, forming a polymeric chain running along the c axis. The lattice water molecule is situated on a twofold rotation axis, and links to the perchlorate anion via an O-HÁ Á ÁO hydrogen bond. The long AgÁ Á ÁO separation of 3.200 (4) Å indicates a weak interaction between the perchlorate anion and the Ag I cation. Weak C-HÁ Á ÁO hydrogen bonding occurs between the chain and the lattice water molecule and between the chain and perchlorate anions. Both five-membered rings of the L ligand display envelope conformations; in one five-membered ring, the flap C atom is disordered on opposite sides of the ring with occupancies of 0.65 and 0.35.
We are grateful to the National Science Council of the Republic of China and the Nanya Institute of Technology for support. The synthesis of metal coordination polymers has been a subject of intense research due to their interesting structural chemistry and potential applications in gas storage, separation, catalysis, magnetism, luminescence, and drug delivery (Kitagawa et al., 2004). Roles of anion, solvent and ligand comformations in self-assembly of coordination complexes containing polydentate nitrogen ligands are very intersting (Chiang et al., 2008;Yeh et al., 2008;Hsu et al., 2009;. The d 10 metal complexes containing 1,4-bis(4,5-dihydro-2-oxazolyl)benzene ligands (L′) have been reported, which show various two-dimensional networks , Wang et al., 2011. The Ag + cations are coordinated with two N atoms from two 1,2-bis(4,4-dimethyl-4,5-dihydrooxazol-2-yl)ethane (L) ligands (
These were washed with methanol and collected in 68.2% yield.

Refinement
H atom of the water molecule, H7C, was located in the difference electron density map and refined isotropically, while the other H atoms were constrained to ideal geometries, with C-H = 0.96 (methyl) or 0.97 (methylene) Å and U iso (H) = 1.2U eq (C). The C2 atom of the the dihydrooxazol-2-yl ring is disordered over two sites with occupancy factors of 0.65 and 0.35.

Figure 2
The packing diagram shows the Ag···O interactions and O-H···O hydrogen bonds among the one-dimensional chains. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Occ. (