STRUCTURAL ASPECTS OF THE COORDINATION OF TRIETHYLPHOSPHINEGOLD(I) TO2-THIOURACIL - A COMPARISON BETWEEN THEORY AND EXPERIMENT

The interaction of the thionucleobase 2-thiouracil with the triethylph osphinegold(I) cation has been examined employing ab initio molecular orbital theory. Deprotonation of 2-thiouracil (2-TUH) and subsequent a ssociation with [Et3PAu](+) leads to the formation of [Et3PAu(2-TU_H)] ; a comparison of calculated and experimental geometric parameters rev eals a high degree of agreement. The interaction of two [Et3PAu](+) ca tions with twice deprotonated 2-TUH indicates that the most stable din uclear structure is one where coordination occurs via the sulfur and o ne of the nitrogen atoms leading to almost linear P-Au-S and P-Au-N ar rangements, respectively.