Tri- and tetraamines

An extensive study of the conformational behavior of perhydroazepine 66 was carried out by Espinosa and coworkers105. This pure force field based analysis, with no reference to experiment or other theoretical methods, was part of a series of studies on cycloheptane, cycloheptene and some of their oxygen, sulfur and nitrogen heterocyclic analogs. MM2 

FIGURE 7. The lowest-energy form of each of the conformational families of perhydroazepine 66 as calculated by MM2 and MM3 (MM2 relative energies in parentheses) 

SCHEME 5. Schematic representation of the conformational equilibrium of perhydroazepine 66 as a function of the two dihedral angles 234 and a 1765. Continuous lines represent C/TC and B/TB families. TC -e- B transitions are represented by broken lines, (x) and ( ) represent minimum and maximum energies, respectively. Reproduced with permission from Reference 105 

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An important mode of oxidation for -phenylenediamines is the formation of ben2oquinonediimines, easily obtained by oxidation with silver oxide in ether solution (17). DHmines undergo 1,4 additions with amines to generate tri- and tetraamines which readily oxidi2e in air to highly conjugated, colored products. An example of this is the formation of Bandrowski s base [20048-27-5] when -phenylenediamine is oxidi2ed with potassium ferricyanide (18). 

The choice of tridentate amine has a critical impact on the coordination mode of the ambidentate nitrite ligand, N02.499,500 Complexes with substituted tri- and tetraamines have shown that bulky substituents may prevent the formation of the -N02 bridged polymeric complexes, and the intramolecular hydrogen network may stabilize N coordination of nitrite. 

In addition to the well-known compounds putrescine, spermidine, and spermine, many other simple di-, tri-, and tetraamine compounds are... 

Many polyamines are now available from Aldrich, Fluka, Phaltz and Bauer, Sigma, and TCI chemical companies. The available compounds include tri-and tetraamines with a mix of ethylene, trimethylene, and tetramethylene units between the nitrogen atoms. Of particular interest are tetraamines where the two internal amines are tertiary and the terminal amines are secondary. These compounds can be used in the ring closure reaction to form the peraza-crowns. 

The tri- or tetraamine complex of copper(I), prepared by reduction of the copper(II) tetraamine complex with copper metal, is quite stable ia the absence of air. If the solution is acidified with a noncomplexiag acid, the formation of copper metal, and copper(II) ion, is immediate. If hydrochloric acid is used for the neutralization of the ammonia, the iasoluble cuprous chloride [7758-89-6], CuCl, is precipitated initially, followed by formation of the soluble ions [CuClj, [CuCl, and [CuCl as acid is iacreased ia the system. 

This method was successfully employed for the preparation of the tris(dialkylamino) derivatives 62-64 and tetraamines 35 and 65-68. Some details are given in Table 3. For the synthesis of 63 and 65-67, the ortho-dialkylamino groups were introduced by means of nucleophilic substitution of one or both of the methoxy groups in compound 69 with the appropriate dialkylamine (Scheme 5). In other cases this was achieved via exhaustive methylation of the amino groups in mono-, di- or polyamines. 

Complexes of Ni11 or Cu11 with 1,2- 1,3- or 1,4-diamines react with acetone in 2+2 condensations to form [14]-, [15]-, [16]-, or [18]-membered diamine-diimine macrocycle compounds, e.g., (15) and (16), formed from en, or with 3,3-tri or tetraamines in 1 + 1 condensations to form a diamine-monoimine or triamine-monoimine macrocycle compounds, respectively, e.g., (19) formed from 2,2,2-tet (Scheme 5).31... 

Three new macrocyclic ligands (187) when complexed with zinc(II) could promote ester hydrolysis and a kinetic study of the hydrolysis of 4-nitrophenyl acetate in Tris buffer at pH 8.63 in 10% (v/v) MeCN was earned out with these.153 The hydrolysis of lipophilic esters is also catalysed by zinc(H) in a complex of a long alkyl-pendant macrocyclic tetraamine (188) in micellar solution.154 A study with a copper chloride-containing micelle has compared its effectiveness in the hydrolysis of esters and amides.155... 

This type of reaction was reported for tris(2-methoxyethyl)aminei and for the tetraamine tris(2-diethylaminoethyl)amine (Etetren). The latter was also obtained by alkylation of A, A-diethylethylenediamine with (C2H5)2NCH2CH2-Cl. 7 The corresponding methyl derivative tris(2-dimethylaminoethyl)amine (Mestren) was prepared by methylation of tris(2-aminoethyl)amine (tren). Similarly, methylation of tris(2-thiolethyl)amine was used to prepare tris(2-methylthioethyl)amine (D = SCHs). The method reported here (Sec. C) seems more efficient, in that it avoids the intermediate synthesis of N(CH2CH2-SH)a and is based on the reaction above with NaSCHs the sodium methyl-mercaptide is either prepared in advance or in situ by the reaction of CH3SH with NaOCHa. 

The vNiN vibrations were assigned in 2,6-diacetylpyridine dioxime at 416, 341 and 276 cm and at 370 and 265 cm in hexaamine complexes, at 410 and 334 cm in triethylendiamine derivatives, around 240 cm" in pyridine derivatives and in imidazol complexes between 325 and 210cm"Gobemado-Mitre et al attributed the vCuN mode in copper complex of naphthalocya-nine to those bands observed at 341 and 221 cm" In Cu(II) tri-azamacrocycles it has been proposed the bands at 383 and 314 cm" as due to vCuN. This mode was observed in copper complexes of cyclam at 437 cm" and in Cu(II) hexaazacyclophane at 390 and 280 cm" In phenantroline Cu(II) complexes the vCuN vibration was identified with the bands at 300 and 430 cm" In the case of the Zn complexes, some tetraamine derivatives display the vZnN band at 432cm" and in triethylendiamine complexes were observed at 405 and 291 cm" in imidazole complexes the vZnN mode was assigned to the bands between 325 and 210 cm" The vZnN mode of bis(phenylhydrazine)-l, 10-phenantroline Zn(II) was attributed to the bands at 376 and 267cm" ... 

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