Amalgamating at the Molecular Level. Study of the Strong Closed-Shell Au(I)···Hg(II) interaction. José M. López-de-Luzuriaga,* a Miguel Monge, a M. Elena Olmos, a David Pascual a and Tania Lasanta a a Departamento de Química, Universidad de La Rioja, Grupo de Síntesis Química de La Rioja, UA-CSIC. Complejo Científico-Tecnológico, 26004-Logroño, SPAIN. ELECTRONIC SUPPLEMENTARY INFORMATION Supplementary Material (ESI) for Chemical Communications This journal is (c) The Royal Society of Chemistry 2011