The straightforward reaction of thiamacrocycles (1,4,7,10,13,16-hexathiacyclooctadecane ([18]aneS6), 1,4,7,10,13-pentathiacyclopentadecane ([15]aneS5), 1,4,8,11-tetrathiacyclotetradecane ([14]aneS4), and 1,4,7-trithiacyclononane ([9]aneS3)) with RuCl2(dmso)4 in CHCl3 or CH2Cl2 has produced several crystalline compounds which have been structurally characterized. X-ray crystallographic analysis reveals the following complexes: [trans-RuCl2([18]aneS6)] (1), [(RuCl2(dmso))2[15]aneS5] (2), [cis-RuCl2([14]aneS4)] (3), and [RuCl2([9]aneS3)(dmso)] (4). As anticipated all low-spin Ru(II) ions have distorted octahedral environment. Unforeseen was the formation of a dinuclear compound, with one sulfur atom of [15]aneS5 forming a bridge between two cis-RuCl2 moieties. For all these structures, the Ru–S separations range from 2.29 to 2.36 Å (thiaether) with much larger values for Ru–S–Ru bridge (2.509 (3) and 2.499 (3) Å), and 2.24–2.25 Å (dimethyl sulfoxide). The crystallographic parameters at − 100 °C are as follows: 1: monoclinic, space group P21/c; a, b, c (Å): 8.8975 (3), 11.9747 (5), 9.5666 (4); β = 109.923 (1)°. V = 958.27 (7) Å3, Z = 2; 2: monoclinic, space group P21/c; a, b, c (Å): 23.029 (5), 8.3909 (19), 14.220 (3); β = 102.118 (6)°. V = 2686.6 (10) Å3, Z = 4; 3: monoclinic, space group P21/n; a, b, c (Å): 8.5071 (12), 14.272 (2), 12.9361 (18), β = 93.566 (4)°. V = 1567.6 (4) Å3, Z = 4; 4: monoclinic, space group P21/c; a, b, c (Å): 8.2424 (5), 12.4688 (7), 14.8408 (10), β = 104.546 (2). V = 1476.34 (16) Å3, Z = 4 (the last structure is practically identical to already measured at different temperature).
Graphical Abstract