摘要: Recent progress in topological stereochemistry has led to the synthesis of molecules whose embeddings 3—spaces are topologically non—trivial, for example, molecular Mabius strip which was synthesized 1982 by Walba, Richards and Haltiwanger [WRH]. Synthesis a knotted molecule been sought some time finally now achieved Dietrich—Buchecker Sauvage [DS]. Also, recent work with DNA resulted various knots being even used help understand recombinant mechanisms [WDC].