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Abstract The overarching goal of this study is to effect the elimination of platinum from adducts withcis–C≡C−Pt−C≡C‐ linkages, thereby generating novel conjugated polyynes. Thus, the bis(hexatriynyl) complextrans‐(p‐tol3P)2Pt((C≡C)3H)2is treated with 1,3‐diphosphines R2C(CH2PPh2)2to generate (R2C(CH2PPh2)2)2Pt((C≡C)3H)2(14; R=c,n‐Bu;e,p‐tolCH2). These condense with the diiodide complexes R2C(CH2PPh2)2PtI2(9 a,c) in the presence of CuI (cat.) and excess HNEt2to give the title macrocycles [(R2C(CH2PPh2)2)Pt(C≡C)3]4(16 c,e) as adducts of the byproduct [H2NEt2]+I−(30–66 %). DOSY NMR experiments establish that this association is maintained in solution, but NaOAc removes the ammonium salt. The bis(triethylsilylpolyynyl) complexes (n‐Bu2C(CH2PPh2)2)Pt((C≡C)nSiEt3)2(n=2, 3) are synthesized analogously to14 c. They react with I2at rt to give mainly the diiodide complex9 cand the coupling product Et3Si(C≡CC≡C)nSiEt3. The possibility of competing reactions giving IC≡C species is investigated. Analogous reactions of the Pt4C24macrocycle16 calso give9 c, but no sp13C NMR signals or mass spectrometric Cxz+ions (x=24–100) could be detected. It is proposed that some cyclo[24]carbon is generated, but then rapidly converts to other forms of elemental carbon. No cyclotetracosane (C24H48) is detected when this sequence is carried out in the presence of PtO2and H2.
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The use of DOSY experiments to determine the solution structures of coinage metal pyrazolates: The case of {[3,5‐(CF 3 ) 2 Pz]Ag} 3
Abstract A series of DOSY experiments have been carried out to determine the solution stoichiometry of silver(I) 3,5‐bis (trifluoromethyl)pyrazolate species. This compound exists as a trimer in the solid state (n = 3) but in solutions of chlorinated solvents, the DOSY data suggest the presence of a mixture of solvent stabilized monomer (n = 1) and dimer (n = 2) in equilibrium. Different approximations have been used including the Stokes–Einstein and the Stokes–Einstein–Gierer–Wirtz equations. Some methodological problems are discussed.
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- Award ID(s):
- 1954456
- PAR ID:
- 10363651
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Magnetic Resonance in Chemistry
- Volume:
- 60
- Issue:
- 4
- ISSN:
- 0749-1581
- Format(s):
- Medium: X Size: p. 442-451
- Size(s):
- p. 442-451
- Sponsoring Org:
- National Science Foundation
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