Synthesis and structures of bis(tetraphenylphosphonium) tetracarbonyl(tetratellurido)metalate(2-) (metal = chromium, tungsten) containing a polytelluride ligand derived from a soluble Zintl anion

Abstract

969p-oxo groups (2.050 A) is 0.047 shorter than the average trans distance (2.097 A). This elongation trans to the p-oxo groups for the Mn(IV) ion is often observed for oxo-bridged species,22 including 1. Unlike the situation for 1 and 3, mixed-valence complexes 2 and [(TACN)Mn(p-O)2(p-OAc)Mn(TACN)]3+(4)Iza do not have distinguishable Mn(II1) and Mn(IV) ions. Cyclic voltammetry of 3 reveals a quasi-reversible redox wave with E, = 0.87 V, E, = 0.79 V, and E l / 2 = 0.83 V (vs Ag/Ag+), corresponding to the 111, IV/IV,IV couple and a wave at E , = 0.15 V, E, = -0.02 V, and E I l 2 = 0.085 V, due to the III,IV/III,III couple.23 The former couple for 1, and 2, lies at significantly higher values: E I l 2 = 1.25 and 1.26 V, respectively.' The EPR spectrum of 3, displayed in Figure 2, bears a remarkable resemblance to that for a recently reported species suspected of being a peroxy-bridged Mn"Mn"' complex.24 Preliminary simulations for the 16-line pattern in Figure 2 yielded spectral parameters A, = 150 X IO4 cm-I and A2 = 78 X lo4 cm-I, in good agreement Synthesis and Structures of [(C,H,),P],[M(CO),Te,] (M = Cr, W), Containing a Polytelluride Ligand Derived from a Soluble Zintl Anion 13007-92-6; W(CO),, 14040-1 1-0; K2Te3, 67488-76-0; K2Te,, 78547-42-9; K2Te,, 112817-28-4; Mo(CO),, 13939-06-5. Supplementary Material Available: Tables of atomic coordinates and isotropic temperature factors, cation and solvent distances and angles, anisotropic temperature factors, and hydrogen atom parameters (1 7 pages); a table of observed and calculated structure factors (63 pages). Ordering information is given on any current masthead page. (22) Schrobilgen G. J.; Bjorgvinnson, M., in press.

Carbonylchromium Monotelluride Complexes [Et4N]2[Te{Cr(CO)5}n] (n = 2, 3): Two Important Intermediates

“…Although several approaches to the carbonylchromium polytelluride complexes were reported by the usage of "Zintl" tellurides to react with Cr(CO) 6 in various organic solvents, there is no feasible route for the direct isolation of the chromium carbonyl monotelluride intermediates. 4,5,7 After numerous attempts, we found that use of Te powder with 3 equiv of Cr(CO) Conversely, 2 can convert back to 1 upon the reaction with Cr(CO) 6 in MeCN. The similar transformation of dichromium complex to trichromium complex by the addition of the unsaturated Cr-(CO) 5 group has been found in the sulfur-tungsten analogue.…”

“…The trichromium complex 1 is found to be stable in MeOH and THF for quite some time. Surprisingly, when [Et [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] in the forced conditions. Very recently, the C-O bond breakage of MeOH was reported in the Bi-Cr-CO system; however the reactive species has been as yet unknown.…”

“…3 For the analogous Te-Cr-CO system, the structurally characterized examples are limited to the open structures such as [Te 2 {Cr(CO) 5 } 4 ] 2-, 4 [Te 3 {Cr(CO) 5 } 4 ] 2-, 4 [Te 2 {Cr(CO) 5 } 2 ] 2-, 5 and [Te 3 {Cr-(CO) 5 }] 2-5 and the closed ring complexes [Te 4 {Cr-(CO) 5 } 4 ], 6 [Te 2 {Cr(CO) 4 } 2 {Cr(CO) 5 } 2 ] 2-, 4 and [Te 4 Cr-(CO) 4 ] 2-. 7 The polychromium carbonyl monotelluride complex was only limited to the Cp ring stabilized neutral compound [Te{CrCp(CO) 2 } 2 ]. 8 We wish to report the first isolation of the monotelluride-bridged trichromium and dichromium anionic complexes [Te{Cr-(CO) 5 } 3 ] 2and [Te{Cr(CO) 5 } 2 ] 2-, which can be isolable in the presence of [Et [2] and their transformations to other telluriumcontaining polychromium carbonylates are described and the interesting structural features of the resultant complexes are also compared.…”

Reaction of [Et4N]2[Te{Cr(CO)5}n] (n = 2, 3) toward Electrophiles: Reactivity Comparison and Theoretical Calculations

“…In contrast, the chemistry of the analogues of tellurium, the heavier congener of sulfur, has been much less explored . While the chemistry of iron-containing carbonyl telluride complexes has been well studied, the study of chromium-containing carbonyl tellurides remained relatively rare mainly due to a lack of practical synthetic methodologies. − For the Te−Cr−CO system, the structurally characterized examples were limited to some open structures such as [Te 2 {Cr(CO) 5 } 4 ] 2- , [Te 3 {Cr(CO) 5 } 4 ] 2- , [Te 2 {Cr(CO) 5 } 2 ] 2- , and [Te 3 {Cr(CO) 5 }] 2- , and only several ring complexes [Te 4 {Cr(CO) 5 } 4 ], [Te 2 {Cr(CO) 4 } 2 {Cr(CO) 5 } 2 ] 2- , and [Te 4 Cr(CO) 4 ] - were reported . Because of our interest in the chemistry of main group-transition metal carbonyl complexes, − two monotelluride-bridged dichromium and trichromium anionic species [Te{Cr(CO) 5 } n ] 2- ( n = 2, 3) were successfully synthesized from the reaction of Te powder with Cr(CO) 6 in KOH/MeOH solutions 10a.…”

Synthesis and structural characterization of the neutral pentagonal-prismatic Co11Te7(CO)10 cluster in a matrix of [Cp′4Nb2(CH3Te)Te]I (Cp′ = tBuC5H4)

“…Another strategy for the synthesis of metal telluride clusters employs the oxidative decarbonylation of metal carbonyls by polytelluride anions [5][6][7][8][9]. In this context we were interested to cleave the Te-Te bond in Cp′ 2 Nb(g 2 -Te 2 )H (Cp′ = tBuC 5 H 4 ) (1) [10] by reductive means.…”