Sarcophaginates formation

Fig. 30. Schematic formation of the D3-symmetrical complexes [i (L7-2H)3]3 in water with numbering scheme. The representation of [i (L7-2H)3]3 corresponds to the crystal structure of [Cr(sarcophagine)][La(L7-2H)](Fl20)8...

Nitrosation of [Co(diAMsar)]3+ cation in the presence of chloride anion led to the formation of cobalt dichlorosarcophaginate, the reduction of which with zinc dust and subsequent treatment with H2O2 and HCl gave the simplest [Co(sar)]Cl3 sarcophaginate [94, 101] ... 

Cross-linking of [Co(sen)]Cl3 semisarcophaginate with nitro-methane and formaldehyde led to the formation of the [Co(NOMEsar)]Cl3 complex readily reducible to [Co(AMMEsar)]Cl3 sarcophaginate. A detailed procedure for the preparation of [Co(NOMEsar)]Cl3 complex was reported in Refs. 101 and 118. Nitrosation of [Co(AMMEsar)]Cl3 clathrochelate accompanied by reduction with zinc dust resulted in the [Co(MEsar)]Cl3 complex [94] ... 

Co(diAMsar)]3+ cation, nitrosation of the [Co(AMMEsar)]3+ cation led to the formation of "orange" and "yellow" fractions separated by lEC. The orange fraction contained the products of nucleophilic addition to carbanion without rearrangement (expected [Co(ClMEsar)]Cl3 (ca 70%) and [Co(HOMEsar)]Cl3 (ca 20%)sarcophaginates). The yellow fraction contained the product of nucleophilic addition to carbocation with rearrangement - [Co((ClME)MEabsar)]Cl3 clathrochelate (ca 10%) [101],... 

The following lEC separation (hydrochloric acid was used as eluent) and the vapor diffusion of ethanol into an aqueous solution of the cobalt(III) NsSes-sarcophaginate led to the formation of [Co(MEN0sar-N3Se3)]Cl3 5H20 crystals [125]. 

Reduction of complex 1 with zinc dust in aqueous hydrochloric acid followed by oxidation with hydrogen peroxide led to the formation of sarcophaginate 2. 

The subsequent dealkylation of a heterocyclic nitrogen atom led to the formation of [Co(MEPYsar)]Cl4-4H20 and [Co(MEQNsar)]Cl4 3H2O sarcophaginates [135],... 

The interaction of the free ligand with cobalt(II) perchlorate in the presence of AgC104 as a precipitant in the nitromethane-methanol mixture made it possible to isolate the [Co(diME l,3pnsar-S6)](C104)3 clathrochelate. The reduction of this clathrochelate with sodium dithionate led to the formation of a cobalt (II) complex that readily produced a free sarcophagine [147],... 

The reduction of triimine sarcophaginate [Co(Me8tricosatriene-sar)]3+ and [Co(Me5tricosatrienesar)]3+ cations with NaBH4 in aqueous solution at pH 10 led to the formation of saturated cobalt(II) and cobalt(III) sarcophaginates [151] ... 

The reaction of vanadium (III) V(acac)3 acetylacetonate with free diAMsar ligand in aqueous ethanol at 40°C for three days led to the formation of a vanadium(IV) [V(diAMHsar-2H)](S206)2 2H20 sarcophaginate. The central ion presumably was oxidized by air oxygen. The isolated complex is stable over a wide pH range (1-10) but decomposes in the presence of oxidants [167]. 

The formation of platinum(III) [Pt(diAMsar)] + sarcophaginate by the y-radiolysis of [Pt(diAMsar)]X4 samples (where X = CF or CF3SO3I was detected by EPR spectroscopy [156], The strong split signals in the EPR spectra were observed at 4 and 77K and did not disappear even after storage of the samples at room temperature for several days. Since i Pt isotope with nuclear spin 1 - 1/2 is a dominant, the EPR spectrum must contain a triplet with the relative peak intensities equal to 1 4 1. Nearly the same spectrum (g = 2.01, the hyperfine interaction constant A 50G) was observed for [Pt(diAMsar)](CF3SO),3 sarcophaginate. For a chloride complex, the spectrum (g = 2.01, A 60G) is more diffuse, which may be due to the... 

The coordination of the alkaline metal ions by three anthracene-appended Ns-sarcophaginates was studied by H, and Li NMR spectroscopies in alcohol media [205]. No evidence was found for complex formation with sodium and potassium ions. In contrast, all these ligands readily bound the smaller Li ion. The Li NMR spectra of preliminarily synthesized clathrochelate lithium complexes contained a sharp peak, shifted downfield with respect to the free ion. Li ion coordination was clearly detected by and Li NMR spectra in the alkaline methanol solution of the ligands on the addition of an excess of Li ion, the Li NMR spectrum showed two sharp peaks, one due to the free ion and another peak downfield-shifted up to 3.3 ppm due to the encapsulated one. The simultaneous presence of these peaks denotes a slow exchange of encapsulated lithium ion on the NMR... 

The fact that the synthesis of sarcophaginates and sepulchrates proceeds via the formation of an imine complex was also confirmed by isolation of the semiclathrochelate [Co(sen)]- + complex (as a by-... 

Due to a larger cavity size, the redox potentials of the compounds with capten ligand are higher than those of Ne-sarcophaginates. The X-ray data for [CoiiTazacapten)] + and [Co (azacapten)]2+ cations (see Section 3.1) reveal two factors that govern the E value. These are strain enhancement and lowering of the stability of the cobalt(III) clathrochelate and increases in the stability of the cobalt(II) clathrochelate. The latter is stipulated by the formation of the low-spin cob alt (II) complex. 

A contracted sarcophaginate [Co((ClME)abcapten)]3+ cation Ev2 =-200 mV, ku = 1.3 x 10 moh s ) was examined as an ETA in photocatalytic systems for hydrogen production [356]. The rate of photoinduced hydrogen formation is controlled by the generation of the excited state S and three processes of the electron transfer ... 

Phosphonium compounds also act as guests in inclusion complexes. The interactions of Co(III) sarcophagine-type cage molecules, [Co(diCLsar)] + or [Co(HONOsar)] +, with mono-phosphonium cations and sodium p-sulfonatocalix[4] arene were studied by Ling and co-workers. They observed the formation of either 1 1 or 1 2 host-guest inclusion... 

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