TY - JOUR
T1 - Acid-Base Chemistry of Transition-Metal-π-Thiophene Complexes
AU - Koczaja-Dailey, Karen M.
AU - Luo, Shifang
AU - Rauchfuss, Thomas B.
PY - 1996
Y1 - 1996
N2 - Studies on the acid-base properties of (arene)Ru(C4R4S) complexes are summarized. The reactivity of π-thiophene complexes towards H+ and OH- depends on the oxidation state of the complex which in turn determines the hapticity of the thiophene ligand. Weak acids protonate (C6Me6)Ru(η4-C4R4S) to give monocationic η4-2-C4R4HS complexes. The S-C(sp3) bond in the C4H5S complex spontaneously cleaves in the solid state as well as in solution to give a 1-thiapentadienyl derivative. For other R groups the protonated thiophene complexes do not undergo C-S bond scission. The thiophene ring in other (C6Me6)Ru(η4-C4R4S) complexes can be cleaved using sources of (C5R′5)Ru+ (R′ = H, Me) to give products containing the Ru2-(μ-η3:η4-SC4R 4) group. This demonstrates the superior ability of two metals to effect C-S bond activation. In the case of Ru(II) complexes, such as (arene)Ru(η5-C4R′4S)2+, their C-S bonds are easily cleaved using aqueous base to give acylthiolato complexes of the type (arene)Ru(η4-SC3R′3COR′). One of the curiosities of this chemistry is that the nucleophile, OH-, initially attacks at sulfur. Amines and ammonia react with the dicationic complexes to give the iminium salts (arene)Ru(η4-SC3R′ 3C(NHR)R′)+.
AB - Studies on the acid-base properties of (arene)Ru(C4R4S) complexes are summarized. The reactivity of π-thiophene complexes towards H+ and OH- depends on the oxidation state of the complex which in turn determines the hapticity of the thiophene ligand. Weak acids protonate (C6Me6)Ru(η4-C4R4S) to give monocationic η4-2-C4R4HS complexes. The S-C(sp3) bond in the C4H5S complex spontaneously cleaves in the solid state as well as in solution to give a 1-thiapentadienyl derivative. For other R groups the protonated thiophene complexes do not undergo C-S bond scission. The thiophene ring in other (C6Me6)Ru(η4-C4R4S) complexes can be cleaved using sources of (C5R′5)Ru+ (R′ = H, Me) to give products containing the Ru2-(μ-η3:η4-SC4R 4) group. This demonstrates the superior ability of two metals to effect C-S bond activation. In the case of Ru(II) complexes, such as (arene)Ru(η5-C4R′4S)2+, their C-S bonds are easily cleaved using aqueous base to give acylthiolato complexes of the type (arene)Ru(η4-SC3R′3COR′). One of the curiosities of this chemistry is that the nucleophile, OH-, initially attacks at sulfur. Amines and ammonia react with the dicationic complexes to give the iminium salts (arene)Ru(η4-SC3R′ 3C(NHR)R′)+.
UR - http://www.scopus.com/inward/record.url?scp=1542529239&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=1542529239&partnerID=8YFLogxK
U2 - 10.1021/bk-1996-0653.ch009
DO - 10.1021/bk-1996-0653.ch009
M3 - Article
AN - SCOPUS:1542529239
VL - 653
SP - 176
EP - 186
JO - ACS Symposium Series
JF - ACS Symposium Series
SN - 0097-6156
ER -