Mn2 i

For the [Mn2(/i-alkoxo)2(/r-carboxylato)2] core (type II), only the benzoate analogues, [Mn2(spa 3-OMe-spa)2(OBz)2] (97) (where H2spa = 3-salicylideneamino-l-propanol), of the acetate complex reported many years ago has been synthesized and structurally characterized. The Mn "Mn separation in (97) is 2.872 A while the bridging Mn—Oaikoxo distances are 1.896 A and 1.939 A. 

For the hexadentate ligands, such as tppn and bbpmax, tetranuclear complexes containing two [Mn2(/i-0)(/i-0Ac)2] " units are obtained. In the cation of the complex [(Mn20(OAc)2)2(bbp-max)2](C104)4 (99) the two dinuclear units are related to each other by a mirror plane. 

Deprotonation of [Mn2(/i-H)(/x-PPh2)(CO)8] may be achieved using KOH EtOH, Na[BH4], NaH, or LiBu.3 The reaction with Na[BH4] in MeCN is described here since it affords the best yield of the desired anionic complex. 

The compound [PPN][Mn2(/i-PPh2)(CO)8] is an orange, air-stable solid. It is soluble in tetrahydrofuran, acetone, and chlorinated solvents, moderately soluble in alcohols and toluene and insoluble in water and hydrocarbon solvents. Solutions of [PPN][Mn2(ju-PPh2)(CO)8] are surprisingly stable as compared to most other transition metal carbonyl anions, decomposing only slowly (days) on exposure to air and/or moisture. The carbonyl IR spectrum of the anion in dichloromethane shows absorptions at 2037 (m), 1947 (s), 1941 (vs), 1914(w), 1888(m), and 1872(m).3... 

Figure 12-19 Proposed transition state structure formed from Mn2+i ATP, and creatine bound in the active site of muscle creatine kinase. Based on EPR spectroscopy with regiospecifically 170-labeled substrates. The electrical charges have been added in one possible constellation. However, hydrogen atoms bound to phospho groups are not shown. After Leyh et al.68i...

A 1.2-mL sample of Sn(SC5H5)(n-C4H9)3 (1.40 g, 3.5 mmol) is added to a suspension of 0.81 g (1.64 mmol) Mn2( i-Br)2(CO)8 (ref. 4) in 30 mL of freshly distilled THF in a 100-mL flask equipped with N2 inlet, stirrer, and dropping funnel. This mixture is stirred at ambient temperature under nitrogen for 1 hr then the volume of solvent is reduced by evaporation in vacuum to 3 mL. Cooling this solution to -15° causes orange crystals of the product to precipitate. These crystals are collected by filtration, washed twice with cold (0°) hexane, and allowed to dry in air. Yield 0.85 g, 94%. Recrystallization of the material can be carried out using hexane as a solvent. 

Taniguchi, I., and Bakenov, Z. 2005. Spray pyrolysis synthesis of nanostructured LiFe, Mn2/),i cathode materials for lithium-ion batteries. Powder Technology 159, 55-62. 

---