Transition Metal Complexes of Positively Charged Crown Thioethers

Treatment of trans-M (CO) _2 (syn- me_8 [16] anes_4) (M=Mo，W) with excess MeOTf gave the tertiary sulfonium ion complex transs - {M (CO) _2 (syn- me_9 [16]anes_4)} OTf (1a， M=Mo；= 1, b, m = w),while the similar reaction with HOTf (1eq .) afforded the secondary sulfonium complex trans-M （CO）（OTf） （syrme_8 H [16] anes_4） (2a， M=Mo；2 b,M=W). The facile evolution of CO observed on protonation and The X-ray structural study of 1aindicate that Ppi-acceptor ability increases in the order，r_2sh ^+> r_2 MeS^+> r_2 . oxidative addition of HOTf to 2 took place stepwisely to give 7-and8-coordinate hydrido complexes trans-{WH (CO) (OTf) (syn- me_8 H [16] anes_4)} OTf (3) and trans-2 {mh (co) (otf) (syn - me 8 h [16] anes译文:4)}(otf) _ 2 (4 a, m = mo;4 b, m = w),The X-ray structural study of 4b indicate that The W atom assumes distorted bicappedOh with a novel W…H- s ^+interaction (W…H1.92*). a similar protonation of 1 with HOTf producedtrans- {MH (CO) (syn- me_9 [16] anes_4)} OTf (5a， M=Mo；5 b,M=W). In 5a the hydrido ligand interacts strongly with the teriary sulfonium S atom to formmo-h-s ^ + 3 c-2e bond (mo-h 1.48,H-S^+1.32*). The methylation of facm (CO) _3 (syn- me_8 [16] anes_4) (M=Mo，W) with an excess of MeOTf give fac {M (CO) _3 (syn- me_9 [16] anes_4)} OTf (6a， M=Mo；6 b, m = w),where the teriary sulfonium ion is uncoordinated. In sharp contrast to the facile protonation of thethiamacrocycle in M (0) complexesthe Mo (IV) complexes trans-Mo (S) _2 (syn_me_8 [16] anes_4) and trans-Mo (N) (n_3) (syn_me_8 [16]as_4) failed to give the corresponding secondary sulfonium ion complexes. Instead，they produced a novel dinuclear trisulfide {mo_2 (mu-S) (S) _2 (syn_me_8 [16] anes_4) _2} (bf_4) _2containing a linear S=Mo-S-Mo=S linkage and parent imido complex transs - {Mo (NH) （OTf）（syn- me_8 [16] anes_4）} OTf (8), respectively。

Treatment of trans-M (CO) _2 (syn-Me_8 [16] aneS_4) (M=Mo, W) with excess MeOTf gave the tertiary sulfonium ion complex trans- {M (CO) _2 (syn-Me_9 [16] aneS_4)} OTf (1a, M=Mo ; =1b, M=W), while the similar reaction with HOTf (1 eq.) afforded the secondary sulfonium complex trans-M (CO) (OTf) (syrMe_8H [16] aneS_4) (2a, M=Mo ; 2b, M=W). The facile evolution of CO observed on protonation and the X-ray structural study of 1a indicate that Ppi-acceptor ability increases in the order, R_2SH^+>R_2MeS^+>R_2S.Oxidative addition of HOTf to 2 took place stepwisely to give 7-and 8-coordinate hydrido complexes trans-{WH (CO) (OTf) (syn-Me_8H [16] aneS_4)} OTf (3) and trans- {MH_2 (CO) (OTf) (syn-Me_8H [16] aneS_4)} (OTf) _2 (4a, M=Mo ; 4b, M=W), respectively. The X-ray structural study of 4b indicate that the W atom assumes distorted bicapped Oh with a novel W・・・H-S^+interaction (W・・・H1.92*). A similar protonation of 1 with HOTf produced trans- {MH (CO) (syn-Me_9 [16] aneS_4)} OTf (5a, M=Mo ; 5b, M=W). In 5a the hydrido ligand interacts strongly with the teriary sulfonium S atom to form Mo-H-S^+3c-2e bond(Mo-H1.48, H-S^+1.32*). The methylation of fac-M (CO) _3 (syn-Me_8 [16] aneS_4) (M=Mo, W) with an excess of MeOTf give fac {M (CO) _3 (syn-Me_9 [16] aneS_4)} OTf (6a, M=Mo ; 6b, M=W), where the teriary sulfonium ion is uncoordinated. In sharp contrast to the facile protonation of the thiamacrocycle in M (0) complexes, the Mo (IV) complexes trans-Mo (S) _2 (syn-Me_8 [16] aneS_4) and trans-Mo (N) (N_3) (syn-Me_8 [16] aneS_4) failed to give the corresponding secondary sulfonium ion complexes. Instead, they produced a novel dinuclear trisulfide {Mo_2 (mu-S) (S) _2 (syn-Me_8 [16] aneS_4) _2} (BF_4) _2 (7) containing a linear S=Mo-S-Mo=S linkage and parent imido complex trans- {Mo (NH) (OTf) (syn-Me_8[16]aneS_4)} OTf (8), respectively.