Discrete and Polymeric Coordination Assemblies Derived from 3-Pyridyl Attached Flexible Phosphoric Triamide Ligand and Copper Salts

  • Arvind K. Gupta
  • Ashok Yadav
  • Ramamoorthy BoomishankarEmail author
Research Article


A new example of phosphonium cation, [P(NH3Py)4]+, (2) featuring 3-pyridyl substituents has been reported. Reactivity of 2 with KOH in methanol have resulted in the formation of a neutral phosphine imine [P(N3Py)(NH3Py)3], 2-H. Treatment of 2 with various metal salts of copper have resulted in a P–N bond cleavage in which the in situ generated phosphoramide ligand [PO(NH3Py)3], 1, has shown to yield interesting kinds of self-assembled structures in macrocyclic, cage and 2D-coordination polymers. Thus, the reaction of 2 with Cu(NO3)2 in methanol gave the supramolecular [M6L8]12+ type cage reported earlier with the phosphoramide 1. Treatment of 2 with a Cu(I) salt in CHCl3 under ambient conditions have lead to the formation of a 20-membered macrocyclic Cu(II) compound [(PO(NH3Py)3)CuCl2]2, 3, via the in situ oxidation of Cu(I). In another reaction, treatment of 1 or 2 with Cu(NO3)2 in a reducing solvent such as dimethylformamide (DMF) under hydrothermal conditions gave a Cu(I) coordination polymer {[Cu2(PO(NH3Py)3)3](NO3)2}n, 4. Crystallographic studies on all these newly synthesized compounds have shown interesting kinds of supramolecular organization for these molecules.

Graphical Abstract

New examples of a phosphonium cation, [P(NH3Py)4]+, and a phosphine imine, [P(N3Py)(NH3Py)3] featuring 3-pyridyl substituents have been reported. Treatment of the phosphonium cation with various metal salts of copper have resulted in a P–N bond cleavage in which the in situ generated phosphoramide ligand [PO(NH3Py)3], has shown to yield interesting kinds of self-assembled structures in macrocyclic, cage and 2D-coordination polymers.


P–N ligands Phosphine imine Phosphonium cation Copper compounds Cationic MOFs 



The authors thank DST, India and IISER, Pune for financial support. AY thanks CSIR, India for a fellowship.

Supplementary material

40010_2014_135_MOESM1_ESM.doc (940 kb)
Supplementary material 1 (DOC 940 kb)


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Copyright information

© The National Academy of Sciences, India 2014

Authors and Affiliations

  • Arvind K. Gupta
    • 1
  • Ashok Yadav
    • 1
  • Ramamoorthy Boomishankar
    • 1
    Email author
  1. 1.Indian Institute of Science Education and Research (IISER), PunePuneIndia

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