Manganese complexes configuration

Cobalt and manganese complexes are cleaved by other nucleophiles with inversion of configuration (55-74%) ... 

Reaction of the Pt complex (13) with (11) gives a silylplatinum complex (14), the silyl group of which has the same configuration as that of (11). The oxidative addition is thus assumed to take place from the front side of the Si—H bond (equation 7). The hydrosilane (11) reacts with a manganese complex (15) to give rise to a complex (16 equation 8), which has a structure similar to the intermediate of the oxidative addition step. °... 

Although even in the IiAUi cleavage of the Si-Pt bonds a reductive elimination process is likely to occur, since the configuration at silicon is almost completely retained, a nucleophilic displacement of the silyl ligand is still conceivable. Deuterium labeling experiments have unambiguously demonstrated this possibility in silyl-manganese complexes (213). 

S) enantiomers of the complex [Mn(C5H5)(NO)COP(C6H5)3]X (2.12)-X was achieved by using natural menthol as the chiral auxiliary. The covalent bond so formed could be readily broken without effecting the absolute configuration of the manganese complex. 

BB The experimental magnetic moments of four manganese complexes are given below. State whether the complexes are high-spin or low-spin. Also Avrite down the electronic configurations (within the and Cg sets of 3[Pg.92]

Ground-state electronic configuration is ls 2s 2p 3s 3p 3i 4s. Manganese compounds are known to exist in oxidation states ranging from —3 to +7 (Table 2). Both the lower and higher oxidation states are stabilized by complex formation. In its lower valence, manganese resembles its first row neighbors chromium and especially iron ia the Periodic Table. Commercially the most important valances are Mn, Mn ", or Mn ". ... 

Tetranuclear manganese(III) carboxylate complexes have three different configurations for their metal centers fused open cubane, planar, or butterfly (see Figure 22). There is only one example of the first type namely [Mn4Q2(OAc)2(BSP)2] (105). The Mn Mn separations in (105) vary between 2.875(1)A and 3.122(1)A. Variable temperature magnetic measurements for (105) indicated weak antiferromagnetic interactions (/=—10.0cm and / = —3.7cm ) between the manganese(III) centers. Cyclic voltammetry of (105) in methanol shows one quasireversible oxidation wave at 0.01 V and two quasireversible reduction waves at about —0.4 V and —0.7 V vs. SCE. 

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