Synthesis of Platinum-Triruthenium Clusters Using the Zero-Valent Platinum Reagent Pt(nb)~3: X-Ray Crystal Structures of Ru~3Pt(CO)~1~1(P-iPr~3)~2, Ru~3Pt(mu-H)(mu~3-eta^3-MeCCHCMe)(CO)~9(P-iPr~ ~3), Ru~3Pt(mu~3-eta^2-PhCCPh)(CO)~1~0(P-iPr~3), Ru~3Pt(mu-H)(mu~4-N)(CO)~1~0(P-iPr~3) and Ru~3Pt(mu-H)(mu~4-eta^2-NO)(CO)~1~0(P-iPr~3)