Polyazolyl chelate chemistry.: 6.: Bidentate coordination of HB(pz)3 (pz = pyrazol-1-yl) to ruthenium and osmium:: Crystal structure of [RuH(CO)(PPh3)2{κ2-HB(pz)3}]

[RuHCl(CO)(PPh3)(3)], [Ru(SnPh3)Cl(CO)(PPh3)(2)], or [RuH(CO)(NCMe)(2)(PPh3)(2)]BF4 reacts with K[HB(pz)(3)] (pz = pyrazol-1-yl) to provide [RuH(CO)(PPh3)(2){eta(2)-HB(pz)(3)}], thermolysis of which proceeds via loss of phosphine and formation of [RuH(CO)(PPh3){eta(3)-HB(pz)(3)}]. The thiocarbonyl analogue [RuH(CS)(PPh3)(2){eta(2)-HB(pz)(3)}] is obtained from [RuHCl(CS)(PPh3)(3)] and K[HB(pz)(3)], thermolysis of which provides [RuH(CS)(PPh3){eta(3)-HB(pz)(3)}]. In chloroform, this species provides [RuCl(CS)(PPh3){eta(3)-HB(pz)(3)}]. [RuH(CS)(PPh3)(2){eta(2)-H2B(bta)(2)}] (bta = benzotriazolyl) results from the reaction of [RuHCl(CS)(PPh3)(3)] with K[H2B(bta)(2)]. The hydride-bridged dinuclear complex [RuCu(mu-H)(CO)(PPh3)(2){eta(3)-HB(pz)(3)}]PF6 results in high yield from the reaction of [RuH(CO)(PPh3)(2){eta(2)-HB(pz)(3)}], with [Cu(NCMe)(4)]BF4. [Os(C6H5)(Co)(PPh3)(2){eta(2)-HB(pz)(3)}] (from [Os(C6H5)Cl(CO)(PPh3)(2)] and K[HB(pz)(3)]) converts on heating to [Os(C6H5)(CO)(PPh3){eta(3)-HB(pz)(3)}].