New multinuclear discrete heteroleptic complexes have been synthesized by mixing Pd(II), 2,2′-bipyridine and N,N′-(1,2-phenylene) diisonicotinamide in a single pot as a new approach. A dimeric molecular rhombus and a trimer in equilibrium are obtained where the dimer is the major product. Similar equilibrium is also observed when classical method is employed for the synthesis. The equilibrium is shifted exclusively in favour of the dimer upon addition of benzene. The complexes are characterized by NMR and ESI-MS methods. Crystal structure of the benzene encapsulated rhombus is presented. © 2010 Elsevier Ltd.

Dillip Kumar Chand

Department Of Chemistry

Venkatachalam Ramkumar

2,2' bipyridine

ISONICOTINAMIDE

N,N' (1,2 PHENYLENE)DIISONICOTINAMIDE

Palladium

unclassified drug

article

Crystal Structure

electrospray mass spectrometry

one pot synthesis

proton nuclear magnetic resonance

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IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

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IIT Madras

Tetrahedron Letters

A survey of the Cambridge Structural Database (CSD) for crystal structures of binuclear coordination complexes, formed by the combination of suitable ligand(s) and Pd(ii) centres which are protected in a cis fashion by 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), tetramethylethylenediamine (tmeda) or ethylenediamine (en), was carried out. The structures of these binuclear complexes could be classified into five different categories-"opened jaws", "helicate", "plateau", "step" and "bow-shaped" based on the relative spatial orientation of the Pd(ii) square planes of the cations and the conformation of the ligand(s). Investigation of the molecular packing in these complexes revealed involvement of the cis-protected Pd(ii) units in the self-assembly of the cations. Cations in the complexes that contained bpy and phen moieties often assembled via π⋯π stacking and C-H⋯π interactions between the aromatic rings of the cis-protecting Pd(ii) units. In contrast, in the en and tmeda complexes, molecular self-organisation in most cases occurred through noncovalent interactions between the cis-protected Pd(ii) units and the ligand, counteranion or included solvent molecules. Hence, the cations can be defined as 'tectons', each of which contains two cis-protecting units, which play the role of 'supramolecular synthons' in the self-assembly of these binuclear complexes. The study of these crystal structures provides information about preferred patterns of molecular association in these complexes, which is invaluable for the crystal engineering of pre-designed self-assembled coordination complexes for desired functions or properties. © 2017 The Royal Society of Chemistry.

CrystEngComm

Cis -Protected palladium(II) based binuclear complexes as tectons in crystal engineering and the imperative role of the cis -protecting agent

One-pot synthesis of self-assembled heteroleptic complexes of general formula [Pdx(tmeda)x(L)y](NO3) 2x is achieved by combining required amount of tmeda, a chosen ligand L and Pd(NO3)2 under suitable reaction conditions. The strategy is devised using our understanding of a special variety of ligand exchange reactions (LER) around palladium(II) centers as modeled in this work. The one-pot synthesis technique is thus considered as an application of the unique LER. © 2013 Elsevier B.V.

Inorganic Chemistry Communications

One-pot synthesis of self-assembled heteroleptic palladium(II) complexes with tmeda: An application of ligand exchange reactions

Palladium(II) has four coordination sites and forms square planar complexes. Discrete self-assemblies are generated by the combination of a variety of palladium(II) components and ligands ranging from bi- to polydentate. The Pd(II) components used are generally of two varieties: cis-protected Pd(II) and unprotected Pd(II). Most common cis-protecting units (X-X) such as ethylenediamine, 2,2'-bipyridine and 1,3-bis(diphenylphosphino)propane and a few other related chelating systems have been exploited for the complexation reactions. The self-assemblies formed are generally represented as [{cis-Pd(X-X)} x(L) y](monoanion) 2x and [Pd m(L) n](monoanion) 2m when generated from the complexation of a suitable ligand (L) with cis-protected Pd(II) and simple Pd(II) units, respectively. When Pd(solvent) 2Cl 2 is complexed with ligands, the solvent molecules are replaced with the incoming ligands, leading to complexes in which the trans positions are occupied by the chloride anions. © 2012 Elsevier B.V.

Coordination Chemistry Reviews

Self-assembled coordination complexes from various palladium(II) components and bidentate or polydentate ligands

A different approach developed for the preparation of palladium(II) based complexes [(Pd(bpy))x(L)y](NO3) 2x is modelled by using 4-phenylpyridine as ligand (L = 1). Various solvent systems are inspected to optimize the reaction condition for the preparation of the model complex [Pd(bpy)(4-phenylpyridine) 2](NO3)2. The model complex is obtained quantitatively as a single product from a 1:1:2 mixture of Pd(NO 3)2, 2,2′-bipyridine and 4-phenylpyridine when stirred at room temperature in CH3CN:H2O (1:1). The same reaction is performed in CD3CN:D2O (1:1) to monitor the progress of the reaction by recording 1H NMR. The kinetic products that formed initially got self-healed to give the desired product with in 6 h. However, in DMSO-d6 spontaneous arrangement leading to the targeted complex was observed and no kinetic product could be detected. When a similar reaction is performed with ethylenediamine instead of 2,2′-bipyridine a mixture of compounds are observed. Theoretical calculation throws some light on the principle behind the success of this method for the bpy based systems. The assembly, [Pd(bpy)(4-phenylpyridine)2](NO3)2 has been characterised by NMR, ESI-MS and single-crystal X-ray diffraction methods. © 2011 Elsevier B.V. All rights reserved.

Inorganica Chimica Acta

A model study of alternative approach toward a class of palladium(II) based self-assembly

Supramolecular Chemistry

Definition and Emergence of Supramolecular ChemistryAdapted in part fromSupramolecular Chemistry, J. W. Steed and J. L. Atwood, Wiley: Chichester, 2nd Ed., 2009.

Accounts of Chemical Research

Self-Assembly, Symmetry, and Molecular Architecture:  Coordination as the Motif in the Rational Design of Supramolecular Metallacyclic Polygons and Polyhedra

Coordination-driven self-assembly in a single pot

Journal	Tetrahedron Letters
ISSN	00404039
Open Access	No