Premium
Structural Relationships obtained from the Coordination of α‐Picolinamide to the (Iminodiacetato)copper(II) Chelate: Synthesis, Crystal Structure, and Properties of (α‐Picolinamide)(iminodiacetato)copper(II) Dihydrate
Author(s) -
BugellaAltamirano Elena,
GonzálezPérez Josefa María,
ChoquesilloLazarte Duane,
NiclósGutiérrez Juan,
CastiñeirasCampos Alfonso
Publication year - 2000
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/(sici)1521-3749(200004)626:4<930::aid-zaac930>3.0.co;2-6
Subject(s) - copper , denticity , crystallography , triclinic crystal system , chemistry , ligand (biochemistry) , chelation , crystal structure , bond length , dithiocarbamate , amide , moiety , stoichiometry , square pyramidal molecular geometry , molecule , stereochemistry , inorganic chemistry , organic chemistry , biochemistry , receptor
The stoichiometric reaction of copper(II) hydroxycarbonate, iminodiacetic acid (H 2 IDA = HN(CH 2 CO 2 H) 2 ) and α‐picolinamide (pya) in water yields crystalline samples of (α‐picolinamide)(iminodiacetato)copper(II) dihydrate, [Cu(IDA)(pya)] · 2 H 2 O ( 1 ). The compound was characterised by thermal (TG analysis with FT‐IR study of the evolved gasses), spectral (IR, electronic and ESR spectra), magnetic and single crystal X‐ray diffraction methods. It crystallises in the triclinic system, space group P1, a = 8.8737(4), b = 10.23203(5), c = 15.7167(11) Å, α = 77.61(1)°, β = 103.89(1)°, γ = 80.32(1)°, Z = 4, final R1 = 0.056. The asymmetric unit contains two crystallographic independent molecules but chemically very similar ones. The Cu II atom exhibits a square base pyramidal coordination (type 4 + 1). pya acts as N,O‐bidentate ligand supplying two among the four closest donor atoms of the metal [averaged bond distances (Å): Cu–N = 1.982(2), Cu–O(amide) = 1.972(2)]. IDA plays a N,O,O′‐terdentate chelating role [averaged bond distances (Å): Cu–N = 2.004(3), Cu–O = 1.941(2) and Cu–O = 2.242(2)]. The coordinating behaviour of pya in 1 is discussed on the basis of its N,O‐bidentate chelating role and the preference of the ‘Cu‐iminodiacetato' moiety [Cu(IDA)] to link the N‐heterocyclic donor of pya in trans versus the Cu–N(IDA) bond. Consistently the ligand pya is able to impose a fac ‐chelating configuration to IDA one around the copper(II) as previously has been reported to mixed‐ligand complexes having a 1/1/2 Cu II /IDA/N(heterocyclic) donor ratio or a closely related 1/1/1/1 Cu II /IDA/N(heterocyclic)/N(aliphatic) one.