Synthesis and Characterization of Cationic Tri Oxygen coordinated Ru Complexes

Abstract

Using the previously synthesized cationic ruthenium hydride complex [( ɳ 6 C 6 H 6 )(PCy 3 )(CO) BF 4 1 ), a method to synthesis O coordinated cationic ruthenium hydride complexes 2 6 was developed. Synthesis of complex [( 1 butanol 3 (PCy 3 )(CO) BF 4 2 ) was done in NMR scale from complex 1 using butanol in CD 2 Cl 2 (1 mL) in a NMR tube. 1 H NMR at 50 °C shows the appearance of a new ruthenium hydride at 1 H NMR: δ 18.8 ppm (d, J = 31.3 Hz, 1H). The complex [(H 2 O) 3 (PCy 3 )(CO) BF 4 3 ) was synthesized using a similar method, with water as a reagent 1 H NMR: δ 17.7 ppm (d, J H P = 30.3 Hz), 31 P NMR: δ 73.0 ppm at 10 °C. By using 1,1,1 tris(hydroxymethyl)ethane as the alcohol source the complex CH 3 C(CH 2 OH) 3 )((PCy 3 )(CO) BF 4 4 ) was synthesized in 80% yield. Under similar experimental conditions the cationic ruthenium hydrid e complex 1, dissolved in acetone to generate complex CH 3 COCH 3 3 (PCy 3 )(CO)Ru(H 2 O)] BF 4 5) as a ketone coordinated complex with a 1 H NMR (400 MHz, acetone d 6 ) δ 4.48 ppm (br.s, 2H), and 31 P NMR (100 MHz, CDCl 3 ) δ73.4 ppm . When complex 1 was dissolved i n dioxane, [(PCy 3 )(CO)Ru(H 2 O 4 )])]++(BF 4 2 6 ) was formed. Compound 6 has 1 H NMR peak at δ 4.48 ppm (br.s, 8H) and 31 P NMR in CDCl 3 δ 55.09 ppm. C omplexes 3 5 have a distorted O h structure with t he longest bond for both Ru C O( 1.828Å) and Ru P Cy 3 2.3130 Å) according to the results of their single crystal X ray analysis.