664980-53-4Relevant academic research and scientific papers
Palladium(II) Complexes of Bowls, Pinwheels, Cages, and N,C,N-Pincers of Starburst Ligands 1,3,5-Tris(di-2-pyridylamino)benzene and 2,4,6-Tris(di-2-pyridylamino)-1,3,5-triazene
Seward, Corey,Jia, Wen-Li,Wang, Rui-Yao,Wang, Suning
, p. 978 - 985 (2004)
The reactions of Pd(II) ions with starburst ligands 1,3,5-tris(di-2-pyridylamino)benzene (tdab) and 2,4,6-tris(di-2-pyridylamino)-1,3,5-triazene (tdat) have been investigated. Complexes with the Pd:tdab (or tdat) ratio being 1:1 and 3:1 have been isolated and characterized. The structures of five new Pd(II) complexes containing the starburst ligands have been determined by X-ray diffraction analyses, which include chelate compounds [PdCl2(tdab)], 1, [(PdCl2) 3(tdab)], 2, [(Pd(OAc)2)3(tdab)], 4, and [(Pd(OAc)2)3(tdat)], 5, and a cyclometalated compound [Pd(OAc)-(NCN-tdab)], 3. The Pd(II) ion in the 1:1 compound 1 is chelated by two pyridyl groups. Similarly, each Pd(II) center in the 3:1 compounds 2, 4, and 5 is chelated by two pyridyl groups. However, these three compounds display distinct structural features: 2 adopts a bowl-shaped structure, 4 has a pinwheel -like structure, and 5 has a up-and-down structure. Compounds 4 and 5 were examined in solution by variable-temperature 1H NMR, which revealed that both compounds retain the pinwheel and the up-and-down structure, respectively. The observed structural preference by 4 and 5 is attributed to both electronic and steric factors.
