Indium complexes nitrogen ligands

Coordination Compounds. A large number of indium complexes with nitrogen ligands have been isolated, particularly where Ir is in the +3 oxidation state. Examples of ammine complexes include pr(NH3)3] " [24669-15-6], prCl(NH3)] " [29589-09-1], and / j -pr(03SCF3)2(en)2]" [90065-94-4], Compounds of A/-heterocychc ligands include trans- [xCX py)][ [24952-67-8], Pr(bipy)3] " [16788-86-6], and an unusual C-metalated bipyridine complex, Pr(bipy)2(C, N-bipy)] [87137-18-6]. Isolation of this latter complex produced some confusion regarding the chemical and physical properties of Pr(bipy)3]3+ (167). 

The earlier discussion of complexes of indium(III) with nitrogen ligands emphasized the importance of six-coordination, and in keeping with this, XH and U5In NMR studies have identified [In(H20)6]3+ as the cation in aqueous solutions of perchloric acid.103,104 Confirmatory evidence has been obtained from dilatometric105 and X-ray diffraction106 methods. Proton... 

A series of earlier papers on complexes of indium(III) with porphyrins,265 and phthalocyanines266-268 has been summarized earlier.7 The structures InLX (L = substituted porphyrin X = Cl, OAc, OPh) imply a square pyramidal stereochemistry with the indium atom situated above the ligand N4 system, and this has been confirmed by X-ray crystallography for X = C1269 and X = Me,270 but for X = MeOS02, the indium atom is in the plane of the four nitrogen atoms.271 A number of Schiff base derivatives have recently been described.272... 

Comparisons to the known structure of indium DTPA and to other divalent metal DTPA bis-amide complexes indicate that the indium cation binds to the three amine nitrogen atoms, the four carboxylate oxygen atoms, and the one carboxairdde oxygen atom of the DTPA monoamide ligand. Addition of an acidic In chloride solution to a ly-ophilized DTPA-octreotide pellet at room temperature readily fomis In DTPA-octreotide, known clinically as OctreoScan. In a rat model of pancreatic carcinoma In DTPA-octreotide showed clear visualization of the tumors and rapid, primarily renal, clearance of the radiophamiaceutical/ Moreover, pretreatment with 1 mg of octreotide prevents uptake of " in DTPA-octreotide in the tumors and adrenal glands, an observation that verifies that this radiolabeled peptide binds to receptor sites. 

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