Synthesis of the Ruthenaboratranes [Ru(CS)(PPh₃){B(mt)₃}]<i>(Ru→B)⁸</i> and [Ru(CO)(CNR){B(mt)₃}]<i>(Ru→B)⁸</i> (mt = methimazolyl, R = <i>^t</i>Bu, C₆H₃Me₂-2,6, C₆H₂Me<sub>3</sub

The reaction of [Ru(CHCH2)Cl(CS)(PPh3)2] with Na[HB(mt)3] (mt = methimazolyl) provides the ruthenaboratrane [Ru(CS)(PPh3){B(mt)3}]. The reaction of [Ru(CO)(PPh3){B(mt)3}] with CO to provide [Ru(CO)2{B(mt)3}] is reversible, while the phosphine-free ruthenaboratranes [Ru(CO)(CNR){B(mt)3}] (R = tBu, C6H3Me2-2,6, C6H2Me3-2,4,6) form irreversibly upon addition of isonitriles (CNR) to [Ru(CO)(PPh3){B(mt)3}]. The crystal structures of the ruthenaboratranes [Ru(CS)(PPh3){B(mt)3}], [Ru(CO)(CNtBu)({B(mt)3}], and [Ru(CO)(CNC6H2Me3-2,4,6){B(mt)3}] are reported.