Ternary complexes metal [Co(II), Ni(II), Cu(II) and Zn(II)] – ortho-iodohippurate (I-hip) – acyclovir. X-ray characterization of isostructural [(Co, Ni or Zn)(I-hip)2(ACV)(H2O)3] with stacking as a recognition factor

Structural and Theoretical Evidence of the Depleted Proton Affinity of the N3-Atom in Acyclovir

“…The all-trans centrosymmetric anions (Figures 2 and A2) have symmetry-related pairs of O-aqua, N7-acv, and O-sulfate donor atoms featuring a rather typical elongated-octahedral Cu(II) coordination, type 4 + 2, with bond lengths of Cu-O(aqua) of 1.963(2) Å, of Cu-N7(acv) of 2.018(2) Å, and of Cu-O(sulfate) of 2.427(2) Å, respectively (Table A2). It seems clear that the, shortest strongly-bound Cu-O(aqua) favor the cooperation of each Cu-N7(acv) bond with an intra-molecular interligand (aqua)O1-H1B···O6(acv) interaction (2.615(3) Å, 157.3 • ) (Table A3), thus leading to the most common MBP of the acv ligand [2][3][4][5][6][7][8][9]12]. This fact imposes the coordination of O-sulfate atoms towards the apical/distal sites of the copper(II) surrounding.…”

“…Likewise, the sulfate ν4 mode consists of two medium intensity bands at 652 and 611 cm −1 , but only one In the Fourier transform infrared (FT-IR) spectrum of 1 (see also Figure A5 for acv·0.68 H 2 O and Figure A6, Table A5), the monodentate sulfate ligands (~C 3v symmetry) split the ν 3 mode in two intense bands at 1122 and 1041 cm −1 , while only one ν 3 band is observed for the free ion at about 1033-1440 cm −1 . Likewise, the sulfate ν 4 mode consists of two medium intensity bands at 652 and 611 cm −1 , but only one at 613 cm −1 for the free ion [4]. The identification of the hydronium ion by FT-IR spectroscopy is not an easy task.…”

“…The steric hindrance on the N3(acv) atom imposed by the acv N9-side chain and ortho-2-amino group should also be considered. at 613 cm −1 for the free ion [4]. The identification of the hydronium ion by FT-IR spectroscopy is not an easy task.…”

“…This acyclic guanine nucleoside analog has proved to bind nucleoside phosphorylases [1] as well as several metal ions. Structural knowledge on mixed-ligand metal-acv complexes (see selected reference [2][3][4][5][6][7][8][9][10][11][12]) supports a variety of metal binding patterns (MBPs) and interesting molecular recognition features. So far, the reported MBPs can be summarized as follows: (a) the formation of the M-N7 bond, with [2][3][4][5][6][7][8][9]12] or without [8,10] the cooperation of an intra-molecular interligand A-H···O6(acv) interaction (A=O or N acceptor); (b) the N7,O6-chelation mode [11]; (c) the µ 2 -N7,O(ol) (see Figure 1) bridging role [3]; and finally, (d) a multi-functional role featured by the µ 3 -N7,O6,O(e)+O(ol), which comprises the bridging, chelating, and tetradentate modes of acv [12].…”

Synthesis and mass spectroscopy kinetics of a novel ternary copper(II) complex with cytotoxic activity against cancer cells

“…We selected o-iodohippuric acid (I-hipH), a compound used for the detection of the adrenal gland in gammagraphy analysis, as an ancillary ligand and as a lead molecule for further drug design [17,18]. The N-H peptide bond of this amino acid derivative is not prone to interact with metal ions by coordination in hippuric derivatives [19][20][21]. In addition, the peptidic bond of this N-substituted glycine derivative is perpendicular to the aromatic ring group because of steric hindrance of ortho-iodophenyl moiety [19].…”