The reactions of Ph2P(CH2CH2O)nCH2CH2PPh2 (n = 4, 5) ligands with Rucl2(CO)3(THF) give a variety of complexes of the type [cis,cis,traras-RuCl2(CO)2{Ph2P(CH2CH2O)nCH2CH2-PPh2-P,P '}]m. Multinuclear NMR and IR spectroscopic studies indicate that the major product in each reaction is the mononuclear (m = 1) complex in which the Ph2P(CH2CH2O)n-CH2CH2PPh2 ligand spans two trans positions. The minor products are polynuclear (m = 2, 3,…) complexes in which each Ph2P(CH2CH2O)nCH2CH2PPh2ligand bridges two rutheniums. X-ray crystal structures of cis,cis,trans-RuCl2(CO)2{Ph2P(CH2CH2O)4CH2CH2-PPh2-P,P'}, 4a, (monoclinic space group P21/n, a = 10.194(1), b = 22.907(3), c = 15.259(2) Å; β = 92.46(1)°; V = 3560.0(8) Å3; Z = 4) and [cis,cis,trans-RuCl2(CO)2{μ-Ph2P(CH2CH2O)4-CH2CH2PPh2-P,P '}]2·(CH3)2CO, 4b·(CH3)2CO, (monoclinic space group P21/a, a = 18.976(3), b = 22.076(5), c = 10.426(8) Å; β = 111.64(1)°; V = 4060(1) Å3; Z = 4) confirm these conclusions. The monomeric 4a is a rare example of an octahedral complex with a trans-spanning bis(phosphine) ligand. Two different rotamers of 4a are observed in the solid state. In the major rotamer the trans-spanning ligand passes between one chloride and one carbonyl while in the minor rotamer the trans-spanning ligand passes between the two chlorides. The dimeric 4b is the first example of a dimetallacrown ether. The trans phosphines in 4b cause the formation of two, distinct metallacrown ether sites separated by a chloride and a carbonyl ligand on each ruthenium. © 1995, American Chemical Society. All rights reserved.
