Dalton Trans. Dalton Trans. Hybrids between classical and metallacalix[4]arenes based on uracil and cis-PtIIL2 entities (L = P(Ph)3 or L2 = 2,2'-bipyridine) Das N. Sanz Miguel P. J. Khutia A. Lazar M. Lippert B. 2009 research-article