tr~n~-RuCl2( C0)2{ Ph2P(CH2CH20),CH2CH2PPh2-PP '} 1, (n = 4, 5; m = 1, 2, ...) Metallacrown Ethers. X-ray Crystal Structures of a Complex Which Exhibits Rotational Isomers in the Solid State, and [cis,cis,truns-RuCl~(CO)~= {pPh2P(CH2CH20)4CH2CH2PPh2=P,P '}12, an Unusual Dimetallacrown Ether cis,cis,tr~n~-R~C12( C0)2{ The reactions of Ph2P(CH2CH20),CH2CH2PPh2 ( n = 4, 5 ) ligands with RuC12(C0)3(THF) give a variety of complexes of the type [c~s,c~s,~~u~s-RuC~~(CO)~{P~~P(CH~CH~~),C PPhz-PQ ' }Im. Multinuclear NMR and IR spectroscopic studies indicate that the major product in each reaction is the mononuclear (m = 1) complex in which the P~~P(CH~CHZO),-CH2CH2PPh2 ligand spans two trans positions. The minor products are polynuclear (m = 2, 3, ...I complexes in which each P~~P ( C H~C H Z O ) , C H~C H~P P~~ ligand bridges two rutheniums. X-ray crystal structures of cis,cis,truns-RuC12(C0)2{Ph2P(CH2CH20)4CH2CH2-PPhz-PQ '}, 4a, (monoclinic space group P2l/n, a = 10.194(1), b = 22.907(3), c = 15.259(2) A; p = 92.46(1)"; V = 3560.0(8) A3; 2 = 4) and [cis,cis,trans-RuCl2(CO)2{~-Ph2P(CH2CH20)4-CH2CH2PPh2-PQ '}12*(CH&CO, 4b.(CH&CO, (monoclinic space group P21/a, a = 18.976(3), b = 22.076(5), c = 10.426(8) A; /3 = 111.64(1)"; V = 4060(1) A3; 2 = 4) confirm these conclusions. The monomeric 4 a is a rare example of an octahedral complex with a transspanning 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 4 b is the first example of a dimetallacrown ether. The trans phosphines in 4 b cause the formation of two, distinct metallacrown ether sites separated by a chloride and a carbonyl ligand on each ruthenium. = -, 0; n 1 3) ligands to transition These metallacrown ethers readily coordinate hard metal

No abstract

No abstract

Conducting organometallic polymers are an interesting class of materials because they combine the electronic properties of metals with the simpler processing requirements of organic polymers. In an approach to incorporating poly(thiophene) segments into controlled three-dimensional environments, we have synthesized 5,5′-bis(diphenylphosphino)-2,2′bithiophene, Ph 2 P(C 4 H 2 S) 2 PPh 2 , and have reacted this ligand with Mo(CO) 4 (nbd) in a 1:1 ratio. The product of this reaction is a cyclic oligomer, as indicated by the presence of only cis-Mo(CO) 4 absorptions in the IR spectrum and the absence of resonances of free phosphines in the 31 P{ 1 H} NMR spectrum. Size exclusion chromatography of the polymer in THF gives an M h n value of 6.0 × 10 3 and M h w value of 9.7 × 10 3 for the polymer. To better understand the structural features of the polymer, model complexes for the edge, Mo(CO) 5 (Ph 2 P(C 4 H 2 S) 2 -PPh 2 )Mo(CO) 5 , and the corner, cis-Mo(CO) 4 (Ph 2 P(C 4 H 2 S) 2 H) 2 and cis-Mo(CO) 4 (Ph 2 PC 4 H 2 S)H) 2 , of the cyclic polymer have been prepared and characterized. X-ray crystal structures of Ph 2 P-(C 4 H 2 S) 2 PPh 2 and the edge model have also been determined.

A new R,ω-bis(phosphine)-polyether ligand, 1,2-(Ph 2 P(CH 2 CH 2 O) 2 ) 2 C 6 H 4 , has been synthesized and used to prepare a number of conformationally restrained metallacrown ethers. The reaction of 1,2-(Ph 2 P(CH 2 CH 2 O) 2 ) 2 C 6 H 4 and Mo(CO) 4 (nbd) gives a good yield of cis-Mo-(CO) 4 {1,2-(Ph 2 P(CH 2 CH 2 O) 2 ) 2 C 6 H 4 -P,P′}. This complex has been isomerized to trans-Mo-(CO) 4 {1,2-(Ph 2 P(CH 2 CH 2 O) 2 ) 2 C 6 H 4 -P,P′} using both UV light and HgCl 2 catalysis. The reaction of 1,2-(Ph 2 P(CH 2 CH 2 O) 2 ) 2 C 6 H 4 with fac-RuCl 2 (CO) 3 (THF) initially yields a mixture of monomeric and oligomeric cis,cis,trans-[RuCl 2 (CO) 2 {1,2-(Ph 2 P(CH 2 CH 2 O) 2 ) 2 C 6 H 4 -P,P′}] n metallacrown ethers. Surprisingly, the oligomeric metallacrown ethers slowly convert into the monomeric metallacrown ether at ambient temperature in a chloroform-d solution. This does not occur with the conformationally mobile [cis,cis,trans-RuCl 2 (CO) 2 {Ph 2 P(CH 2 CH 2 O) 4 -CH 2 CH 2 PPh 2 -P,P′}] n metallacrown ethers. The X-ray crystal structure of cis-Mo(CO) 4 {1,2-(Ph 2 P(CH 2 CH 2 O) 2 ) 2 C 6 H 4 -P,P′} has also been determined. The four ether oxygens lie in a plane, and the average cross-ring oxygen-oxygen distance is slightly larger than those in metallacrown ethers containing Ph 2 P(CH 2 CH 2 O) 4 CH 2 CH 2 PPh 2 ligands.