<abstract abstract-type="toc"> <title> <x xml:space="preserve">Abstract</x> </title> <p> <graphic position="anchor" id="ga" xlink:href="ark:/27927/pgjn2nxxd4" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" />The 6d electrons of Ac atom involved in excited transitions induce a strong CT-SERS enhancement which can be tuned by changing the conformation of pyridine-Ac@Au<sub>7</sub> complexes.</p> </abstract>