COMPOUNDS OF IRON(III) WITH TRANS-1,4,8,11-TETRAAZACYCLOTETRADECANE-6,13-DICARBOXYLIC ACID - STRUCTURES OF TRANS-(TRANS-1,4,8,11-TETRAAZACYCLOTETRADECANE-6,13-DICARBOXYLATO)IRON(III) PERCHLORATE AND TRANS-(TRANS-1,4,8,11-TETRAAZACYCLOTETRADECANE-6,13-DICARBOXYLATO)IRON(III) TRANS-(TRANS-1,4,8,11-TETRAAZACYCLOTETRADECANE-6,13-DICARBOXYLIC ACID)DICHLOROIRON(III) TRANS-1,4,8,11-TETRAAZONIACYCLOTETRADECANE-6,13-DICARBOXYLIC ACID DICHLORIDE TETRAPERCHLORATE TETRAHYDRATE

The macrocyclic amino acid trans-1,4,8,11 -tetraazacyclotetradecane-6,13-dicarboxylic acid (diacH(2)) forms low-spin Fe-III cations trans-[Fe(diac)](+) (with octahedral diac(2-) with two carboxylato oxygens coordinated trans) and trans-[Fe(diacH(2))(X)(2)]X(X(-)=Cl-,NCS-; with planar tetradentate diacH(2)). The cations are resistant to oxidative dehydrogenation when exposed to the atmosphere in acid solution. The carboxylic acid functions of [Fe(diac)](+) readily form the methyl ester compound trans-[Fe(dimest)Cl](ClO4)(2)(dimest=trans-6,13-bis(methoxycarbonyl)1,4,8,1 1-tetraazacyclotetradecane). Structures are reported for trans-[Fe(diac)](ClO4) with diac(2-) octahedrally coordinated by the macrocycle nitrogens and with the carboxylato oxygens coordinated trans [C12H20ClFeN4O8, M(r)=441.6, monoclinic, space group I2/a, a=12.676(3)Angstrom, b=9.030(2)Angstrom, c=15.103(4)Angstrom, beta=108.4(2)degrees, Z = 4, Fe-N=1.992(3) and 1.995(3)Angstrom, Fe-O=1.895(2)Angstrom] and also for the extraordinary compound trans-[Fe(diac)]-trans- [Fe(diacH(2))Cl-2][diacH(6)]Cl-2(ClO4)(4.)4H(2)O, which has three different centrosymmetric cations, trans-[Fe(diac)](+), similar to the cation of the first compound [(Fe-N=2.010(4) and 1.998(4)Angstrom, Fe-O=1.902(3)Angstrom], trans- [Fe(diacH(2))Cl-2](+) with square planar coordination of diacH(2) by the four macrocyclic nitrogens with trans coordinated chlorides [Fe-N=1.992(4) and 2.004(4)Angstrom, Fe-Cl=2.248(1)Angstrom],and [diacH(6)](4+) with the uncomplexed protonated ligand [C36H82Cl8Fe2N12O32, M(r)=1590.4, triclinic, space group P (1) over bar, a=9.474(2)Angstrom, b=11.535(2) A, c=15.487(3)Angstrom, a=71.67(1)degrees, beta=77.31(2)degrees, gamma=76.61(1)degrees, Z = 2].