A New Macrocyclic N 3 S 2 Ligand and Its Nickel(II), Cobalt(II), Rhodium(III)-103, and Rhodium(III)-105 Complexes Dawn C. Goodman, ² Joseph H. Reibenspies, ² Niranjan Goswami, ‡ Silvia Jurisson,* ,‡ and Marcetta Y. Darensbourg* ,² Contribution from the Department of Chemistry, Texas A&M UniVersity, College Station, Texas 77843-3255, and Department of Chemistry, UniVersity of Missouri, Columbia, Missouri 65211 ReceiVed December 4, 1996 X Abstract: The synthesis, structural characterization, and electrochemical properties of N 3 S 2 -ligated metal complexes of the ligand 4,10-dithia-1,7,13-triazabicyclo[11.3.3]nonadecane are described. Complexes of Ni II , Co II , and Rh III have been characterized by X-ray crystallography as six-coordinate complexes of the pentadentate ligand with Cl - anions occupying the position trans to the secondary amine donor. In addition, the chelation of the N 3 S 2 donor ligand to the reactor-produced radionuclide 105 Rh was shown to give a single product in high yield (>98% at pH 5). The ligand is prepared by the template reaction of (N,N′-bis(2-mercaptoethyl)-1,5-diazacyclooctane)nickel(II), Ni-1, with bis(2-chloroethyl)amine, yielding (S,S′-(3-aza-1,5-pentanediyl)-N,N′-bis(2-mercaptoethyl)-1,5-diazacyclooctane- N,N′,N′′,S,S′)nickel(II) chloride, [Ni(amine)Cl]Cl. Removal of nickel from [Ni(amine)Cl]Cl and subsequent reaction of the ligand with CoCl 2 or RhCl 3 ‚xH 2 O afforded (S,S′-(3-aza-1,5-pentanediyl)-N,N′-bis(2-mercaptoethyl)-1,5- diazacyclooctane-N,N′,N′′,S,S′)cobalt(II) chloride, [Co(amine)Cl]Cl, C 14 H 29 N 3 S 2 CoCl 2 ‚1.75MeOH, and (S,S′-(3-aza- 1,5-pentanediyl)-N,N′-bis(2-mercaptoethyl)-1,5-diazacyclooctane-N,N′,N′′,S,S′)rhodium(III) chloride, [Rh(amine)Cl]Cl 2 , C 14 H 29 N 3 S 2 RhCl 3 , respectively. The blue complex [Ni(amine)Cl]Cl, C 14 H 29 N 3 S 2 NiCl 2 ‚MeOH, contains nickel in an octahedral environment of N 3 S 2 Cl donors and crystallizes in the monoclinic space group P2 1 /c with a ) 13.278(3) Å, b ) 11.976(4) Å, c ) 12.928(4) Å,  ) 102.17(2)°, and Z ) 4. The complex [Co(amine)Cl]Cl is fuchsia and crystallizes in the monoclinic space group P2 1 /n with a ) 10.321(2) Å, b ) 7.892(1) Å, c ) 27.684(3) Å,  ) 96.91(1)°, and Z ) 4. Yellow crystals of [Rh(amine)Cl]Cl 2 ,C 14 H 29 N 3 S 2 RhCl 3 , were determined to be in the monoclinic space group C1c1 with a ) 9.655(2) Å, b ) 16.805(4) Å, c ) 11.756(3) Å,  ) 96.29(2)°, and Z ) 4. Introduction The well-known ability for cis-dithiolate complexes of nickel(II) diamine derivatives to template the synthesis of thioethers and thioether macrocycles 1 has been extensively exploited for the sterically constrained (N,N′-bis(2-mercapto- ethyl)-1,5-diazacyclooctane)nickel(II), Ni-1, complex (eq 1). 2-4 Particularly interesting was the possibility of generating five- coordinate Ni II complexes from the reaction of Ni-1 with dihaloalkanes, functionalized with heteroatom donors. In fact, a study of the product generated from reaction of Ni-1 with (BrCH 2 CH 2 ) 2 O revisited the 6 or 4 coordination number preference of nickel(II) as dictated by solvent, counter ion, and chair/boat vs chair/chair configurations of the diazacyclooctane, daco, backbone (eq 2). 3 As depicted in eq 2, there was no evidence for the five-coordinate N 2 S 2 O intermediate. Further examination of factors that influence coordination at the nickel center prompted the synthesis of an N 3 S 2 donor set from the reaction of Ni-1 with (ClCH 2 CH 2 ) 2 NH (eq 3). The N 3 S 2 donor set was interesting for a comparison of coordination chemistry between O and N as axial donors for Ni II , and also for a comparison of metallic derivatives, namely, Co II and Rh III . As implicated by the stick drawings of metal-bound daco, the -methylene group of the boat conformer of the metalla- ² Texas A&M University. ‡ University of Missouri-Columbia. X Abstract published in AdVance ACS Abstracts, May 1, 1997. (1) Thompson, M. C.; Busch, D. H. J. Am. Chem. Soc. 1964, 86, 3651. (2) Darensbourg, M. Y.; Font, I.; Pala, M.; Reibenspies, J. H. J. Coord. Chem. 1994, 32, 39. (3) Darensbourg, M. Y.; Font, I.; Mills, D. K.; Pala, M.; Reibenspies, J. H. Inorg. Chem. 1992, 31, 4965. (4) Goodman, D. C., Buonomo, R. M.; Farmer, P. J.; Reibenspies, J. H.; Darensbourg, M. Y. Inorg. Chem. 1996, 35, 4029. 4955 J. Am. Chem. Soc. 1997, 119, 4955-4963 S0002-7863(96)04187-X CCC: $14.00 © 1997 American Chemical Society