Insertion of a transition metal fragment into a heptaantimonide(3–) anion: synthesis and structure of [Sb₇Mo(CO)₃]^3–

Protonation and Hydrogen Atom Abstraction Reactions in the Synthesis of the [HP7M(CO)3]2- Ions (M = Cr, W)

“…The hydrogen was not crystallographically located. P(6)±P (7) separations (2.968(4) A Ê and 3.307(4) A Ê , respectively) are also typical for these types of compounds [11,14,15,20,22,23] but are larger than the same asymmetries in [P 7 Cr(CO) 3 ] 3± [15]. The larger distortion in the present compound presumably results from the larger size of W relative to Cr.…”

“…The effect of the proton on the P 7 cage can be seen by comparing the structure with [P 7 Cr(CO) 3 ] 3± and related compounds [15,23]. The P(1)±P(2) and P(1)±P(3) bonds are approximately 0.04 A Ê longer than corresponding bonds in [P 7 Cr(CO) 3 ] 3± [15] whereas the other P±P bonds are 0.02 to 0.04 A Ê shorter.…”

Synthesis, Structure, and Reactivities of [η2-P7M(CO)4]3-, [η2-HP7M(CO)4]2-, and [η2-RP7M(CO)4]2-Zintl Ion Complexes Where M = Mo, W

“…Finally, it is of interest to note that Bolle and Tremel have investigated similar reactions between Sb 7 3- and Mo(CO) 4 (bipy) which gave low yields of Sb 11 3- and [η 4 -Sb 7 Mo(CO) 3 ] 3- . , Formation of the latter compound most likely proceeds through an unstable [η 2 -Sb 7 Mo(CO) 4 ] 3- intermediate similar to 4 . Our attempts to isolate this intermediate and the [η 2 -Sb 7 W(CO) 4 ] 3- analog are in progress.…”

“…Although the first reports of naked Zintl ions are now over 100 years old, − the chemistry of these compounds , and, in particular, the first compounds containing Zintl ions bound to transition metals have only recently been reported. − We have been investigating the chemistry of the E 7 3- Zintl ions (E = P, As, Sb) that have the nortricyclane-like structure. In recent papers, we and others have described the synthesis and characterization of the [η 4 -E 7 M(CO) 3 ] 3- complexes ( 1 ), where E = P, As, Sb and M = Cr, Mo, W, in which the nortricyclane-like E 7 3- fragment is transformed into a norbornadiene-type fragment bound η 4 to the M(CO) 3 center. ,, The reactions are accelerated by the use of 2,2,2-crypt “activators” that break the K + --E 7 3- ion pairing in solution and facilitate coordination of the E 7 3- ion to the transition metal center (eq 1)

…”

“…Molecular orbital calculations of complexes 1 show high-lying pnictogen-based lone pairs that are localized on the E(1) site. , It is not surprising, therefore, that electrophiles such as R + , H + , and W(CO) 3 L x react with these complexes at the E(1) site to form [η 4 -XE 7 M(CO) 3 ] n - complexes (X = H, R, W(CO) 3 ). Scheme summarizes the reactions of [η 4 -P 7 W(CO) 3 ] 3- ( 1a ) with various electrophiles (transformations A−C) and the nucleophile carbon monoxide (transformation D) as an example of the chemistry of the [η 4 -E 7 M(CO) 3 ] 3- complexes.…”