Popis: |
Co-crystallization of Na[AuCl4] with 1-methyluracil, C5H6N2O2 (1-MeUH), and 1-methylthymine, C6H8N2O2 (1-MeTH), at pH 0.8 yields predominently salts of composition [Na(1-MeUH)4][AuCl4] (1) and [Na(1-MeTH)(H2O)4][AUCl4]·1-MeTH·2H2O (2). Both 1 and 2 crystallize in space group P 1 with cell dimensions a = 10.531(3), 1, 8.436(5), 2; b = 9.194(3), 1, 10.521(7), 2; c = 7.924(2), 1, 15.917(11) A, 2; α = 96.68(3), 1, 102.61(5), 2; β = 85.09(3), 1, 90.45(5), 2; γ = 103.88(3), 1, 108.10(5)°, 2; U = 738.4, 1, 1306(2) A3, 2; Z = 1, 1, 2, 2. Na+ binding to 1-MeUH is through O(4) in 1 and O(2) in 2. The packing of cations and anions in 1 is special in that infinite stacks of alternating [Na(1-MeUH)4]+ and [AuCl4]− are formed with the metals 3.962(1) A apart. |