Solvent-induced mono- and diplatinum(II) complexes of O3S2-macrocycle

Seo, Joobeom; Park, Ki‐Min; Yoon, Il; Kim, Hyun Jee; Lee, Shim Sung

doi:10.1016/j.inoche.2008.04.018

Cited by 7 publications

(1 citation statement)

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“…When these ligands contain only two sulfur donors, the conformation of the crown will change such that the two sulfur atoms will coordinate cis to one another. Oxathiacrowns containing three sulfur atoms will coordinate to the transition metal in an asymmetric fashion in which two adjacent sulfur donors are cis coordinated, leaving one sulfur atom unbound. − The PtCl 2 binding in 7 most closely resembles that of the larger oxathiacrown ethers because of the asymmetric binding and lack of any apical interactions with the unbound sulfur atom in this complex.…”

Section: Resultsmentioning

confidence: 83%

Metallathiacrown Ethers: Synthesis and Characterization of Transition-Metal Complexes Containing α,ω-Bis(phosphite)-Polythioether Ligands and an Evaluation of Their Soft Metal Binding Capabilities

2015

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The metallathiacrown ethers cis-Mo(CO) 4 {2,2′-(C 12 H 8 O 2 )PO-(CH 2 CH 2 S) n CH 2 CH 2 OP(2,2′-(O 2 H 8 C 12 ))} (n = 2, 3) and cis-Mo(CO) 4 {2,2′-(C 12 H 8 O 2 )POCH 2 CH 2 S-1-(C 6 H 4 )-2-SCH 2 CH 2 OP(2,2′-(O 2 H 8 C 12 ))} have been prepared as soft metal selective molecular receptors. Multinuclear NMR spectroscopy and X-ray crystallography have been used to show that byproducts formed during the syntheses of the metallathiacrown ethers cis-Mo(CO) 4 {2,2′-(C 12 H 8 O 2 )PO(CH 2 CH 2 S) n CH 2 CH 2 OP(2,2′-(O 2 H 8 C 12))} (n = 2, 3) are homobinuclear complexes with cis-Mo(CO) 4 (P-donor)(S-donor) centers. The abilities of the metallathiacrown ethers to bind PdCl 2 and PtCl 2 have been assessed using 31 P{ 1 H} NMR spectroscopy and X-ray crystallography. The complexes showed null results with PdCl 2 ; however, the PtCl 2 experiments showed that the complexes cis-Mo(CO)}]PtCl 2 } (n = 2, 3) complexes. The 31 P{ 1 H} NMR spectra of these complexes suggest a cis-PtS 2 Cl 2 coordination environment in each, which leads to asymmetric binding in the latter complex. Binding of HgCl 2 by the complexes cis-Mo(CO) 4 {2,2′-(C 12 H 8 O 2 )PO(CH 2 CH 2 S) n CH 2 CH 2 OP(2,2′-(O 2 H 8 C 12 ))} (n = 2, 3) has been studied using 31 P{ 1 H} NMR spectroscopy. Each complex was titrated with HgCl 2 , and the quantitative shifts in the 31 P{ 1 H} NMR spectra were fit to a binding mechanism. The n = 2 metallathiacrown ether binds HgCl 2 to form a 1:1 complex with K a = 12.0(0.2) M −1 . In contrast, interaction of HgCl 2 with the n = 3 metallathiacrown ether results in isomerization to the trans complex, and HgCl 2 binds to both isomers. A model has been adapted to fit the titration data of this complex and to extract equilibrium constants for each step in the cycle: the cis−trans equilibrium of the free, K free (0.570 (0.004)), and bound, K bound (0.16 (0.03)), metallathiacrown ethers, as well as the association binding constants for the cis, K cis ([4.1(0.3)] × 10 2 M −1 ) and trans, K trans ([1.1(0.2)] × 10 2 M −1 ), metallathiacrown ethers. The equilibrium constants demonstrate that the cis metallathiacrown ether binds more strongly to the HgCl 2 than does the trans metallathiacrown ether and that the cis−trans equilibrium favors the cis metallathiacrown ether.

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Section: Resultsmentioning

confidence: 83%