186499-19-4Relevant academic research and scientific papers
Selective derivatisation of aza macrocycles
Blake, Alexander J.,Fallis, Ian A.,Gould, Robert O.,Parsons, Simon,Ross, Steven A.,Schroeder, Martin
, p. 4379 - 4387 (1996)
A range of selectively functionalised compounds derived from 1,4,7-triazacyclononane ([9]aneN3), including 4,7-bis(2-hydroxy-2-methylpropyl)-1,4,7-triazacyclononane-1-carbaldehyde (H2L1), 1-benzyl-4,7-bis(2-hydroxy-2-methylpropyl)-1,4,7-triazacyclononane (H2L2) and 1,4-bis(2-hydroxy-2-methylpropyl)-1,4,7-triazacyclononane (H2L3), has been prepared. The structure of H2L3·CHCl3 shows a disordered macrocyclic ring with the major conformer refining to a site occupancy of 0.663(8), and both disordered rings adopting a [333] conformation. The pendant alcohol arms were not disordered and were found to be hydrogen bonded to a CHCl3 solvate molecule with H ... O(1) and H ... O(4) distances of 1.73 and 1.81 A respectively. The structure of Na[Cu(H2L1)(NCMe)][BF4]2[NO 3] shows the copper(II) centre in the [Cu(H2L1)(NCMe)]2+ cation bound to two amine donors and two alcohol donors of H2L1 and to a MeCN molecule. The Cu-N bond lengths lie in the range 1.984(3)-2.015(3) A. Both alcohol donors are protonated, with one short Cu-O(16) bond of 1.963(3) A and one long Cu-O(21) bond of 2.252(3) A. There is also a sixth longer-range interaction of the copper(II) centre with the amide N [N(1)] of H2L1 at a distance of 2.611(5) A, confirmed by the loss of planarity of the C(2)-C(9)-N(1)-C(10)-O(11)-H(10) amide fragment to give a dihedral angle between the planes defined by C(2)-C(9)-N(1) and N(1)-C(10)-O(11)-H(10) of 27.1(4)°. The structure is completed by interaction of O(11) with a Na+ ion which itself bridges to BF4- counter anions leading to a central infinite core of [Na(BF4)2]- aggregates onto which are attached the [Cu(H2L1)(NCMe)]2+ cations. The complex [Cu(H2L2)(OH2)][NO3]2 shows the six-co-ordinate copper(II) centre bound to the three amine and two alcohol donors of H2L2 and to one water molecule. There are four short bonds [to N(7), N(4), O(40) and O(1)] in the range 1.961(5)-2.073(6) A and two longer bonds to N(1) and O(70) at 2.308(5) and 2.313(5) A respectively. The H atoms of the water molecule [O(1)] and one of the pendant arms [O(40)] also make hydrogen-bonding contacts with the nitrate counter ions.
