*4.2.1 Example illustrating the supramolecular interactions of ferrocenyl thiourea*

Dr. Bhajan Lal Bhatia and coworkers synthesized ferrocenyl-based thiourea compounds, i.e., 1-benzoyl-3-(4-ferrocenylphenyl)thiourea (**B16**) and

**57**

**Figure 10.**

**Figure 8.**

**Figure 9.**

*Supramolecular Chemistry and DNA Interaction Studies of Ferrocenyl Ureas and Thioureas*

*The contrast of N,N'-disubstituted ureas functioning as: (a) building blocks for the assemblage of H-bonded chains, as depicted by the crystal structure of di-phenylurea [59] or (b) anion binding groups, as represented by* 

*calculated di-phenylurea:nitrate complex, optimized with DFT at B3LYP/6-31G\* level [56].*

*Supramolecular structures of B16 intervened by secondary bonding.*

*Supramolecular structures of B3 intervened by secondary bonding.*

1-acetyl-3-(4-ferrocenylphenyl)thiourea (**B3**) [60]. Finding displayed two selfregulating molecules which are present in an asymmetrical component in structures of B16 and B3 linked interchangeably to each other through intermolecular NH⋯O and NH⋯S types of hydrogen bonding and secondary interactions

*DOI: http://dx.doi.org/10.5772/intechopen.84412*

*Supramolecular Chemistry and DNA Interaction Studies of Ferrocenyl Ureas and Thioureas DOI: http://dx.doi.org/10.5772/intechopen.84412*

#### **Figure 8.**

*Photophysics, Photochemical and Substitution Reactions - Recent Advances*

structure, the whole process considers experiential observations and a posteriori

Urea group is one such powerful building obstruct that formulates obstinate chains that bind through hydrogen bonding in various surroundings, from solutions [54] to gels and fibrous materials [55], also with crystals [47]. An approach that has been comprehensively discovered since the initial research in crystallography of disubstituted ureas in the late 1960s is the use of symmetrical or asymmetrical N,N′-di-substituted ureas that can deliver widespread multiple building congers for designing of organic solids of crystalline nature. N,N′-di-substituted ureas have the ability to act as H-bond donors by using their two N▬H protons, and play the role of acceptors through utilizing the presence of the lone electron pairs of CO group [36]. Robust one-dimensional hydrogen bonded chains having self-association reinforced promising complementarity between both groups (**Figure 8**) [56], which have been reconnoitered for developing the crystalline

Nanostructured materials on the basis of cylindrical or columnar constructions have been innovated more recently. Thioureas, despite the fact that they can also practice comparatively robust H-bonded motifs [57], have not been as much searched out for the

coherent assemblage of solids of crystalline nature as compared to ureas [58, 59].

*4.2.1 Example illustrating the supramolecular interactions of ferrocenyl thiourea*

compounds, i.e., 1-benzoyl-3-(4-ferrocenylphenyl)thiourea (**B16**) and

Dr. Bhajan Lal Bhatia and coworkers synthesized ferrocenyl-based thiourea

structure of crystal and analytical measurement [53].

**4.2 Supramolecules of ureas and thioureas**

*Noncovalent interactions in supramolecular synthesis.*

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networks repeatedly.

**Figure 7.**

*The contrast of N,N'-disubstituted ureas functioning as: (a) building blocks for the assemblage of H-bonded chains, as depicted by the crystal structure of di-phenylurea [59] or (b) anion binding groups, as represented by calculated di-phenylurea:nitrate complex, optimized with DFT at B3LYP/6-31G\* level [56].*

**Figure 9.** *Supramolecular structures of B16 intervened by secondary bonding.*

**Figure 10.** *Supramolecular structures of B3 intervened by secondary bonding.*

1-acetyl-3-(4-ferrocenylphenyl)thiourea (**B3**) [60]. Finding displayed two selfregulating molecules which are present in an asymmetrical component in structures of B16 and B3 linked interchangeably to each other through intermolecular NH⋯O and NH⋯S types of hydrogen bonding and secondary interactions

**Figure 11.**

*Novel redox active ferrocenyl urea receptors for the purpose of binding and sensing the chiral carboxylate anions and their molar equivalents of (S)-(blue)(R)-(pink) [66].*

non-covalent in nature (π⋯H), which intervene supramolecular structures for B16 and B3 as shown in **Figures 9** and **10** [60].

Determination of some important biological activities usually depends upon these types of secondary nonbonding interactions between the molecules. Greater ability of compounds to associate with macromolecules such as DNA and proteins is observed due to having an ability to make stronger nonbonding interactions [61]. Among the compounds studied, B16 was reported to be associated with more secondary interactions that were apparent from H-bonding data and formation of a supramolecular structure. Therefore, it can be predictable that B16 can have better strapping interaction with DNA that will transform into more elevated biological activities [60].

### **4.3 Chiral recognition of ferrocenyl derivatives**

Now a days, main focus in supramolecular chemistry is chiral recognitions [62] hence designing of enantioselective sensors growing quickly. The encouragement directed us to search for appropriate ways of ascertaining one enantiomer of a specific chiral target board regarding its mirror image [63–65] (**Figure 11**).

The productions of chiral urea's series attached to the ferrocene group which is redox active are discovered [62]. These are able to bind through hydrogen bonding interactions with chiral carboxylates in organic solvents confirmed by spectroscopic and cyclic voltammetric measurements. Cyclic voltammetric measurements have shown that these guests can be sensed via electrochemical approaches in solution. For example, enantioselective nature is prominent enough in the association of protected amino acid, i.e., N-benzenesulfonylproline, through a ferrocenyl-benzyl host that permits the contrary enantiomers to be distinguished in an electrochemical way as depicted in (**Figure 11**) [66].
