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: Development of novel metallodrugs with pharmacological profile plays a significant role in modern medicinal chemistry and drug design. Metal complexes have shown remarkable clinical results in current cancer therapy. Gold complexes have attained attention due to their high antiproliferative potential. Gold-based drugs are used for the treatment of rheumatoid arthritis. Gold-containing compounds with selective and specific targets are capable to assuage the symptoms of a range of human diseases. Gold (I) species with labile ligands (such as Cl in TEPAuCl) interact with isolated DNA, therefore, this biomolecule has been considered as a target for gold drugs. Gold (I) has a high affinity towards sulfur and selenium, due to this gold (I) drugs readily interact with cysteine or selenocysteine residue of the enzyme to form protein-gold(I) thiolate or protein-gold (I) selenolate complexes that lead to inhibition of the enzyme activity. Au(III) compounds due to their square-planner geometries same as found in cisplatin, representing a good source for the development of anti-tumor agents. This article aims to review the most important applications of gold products in the treatment of human colon cancer and to analyze the complex interplay between gold and the human body.

N-heterocyclic carbenes (NHCs) are an eminent class of carbenes having a heterocyclic ring in which a divalent carbon atom is attached directly to a nitrogen atom. In the NHCs, the donation of lone pair is another important research in the dative bonding and not only in NHCs the dative bond plays a functionalized role in the other classes of complex formation like ylidones L → E ← L and carbones L → C ← L. M–NHC bond is L-M sigma-dative bond and NHCs are considered as strong sigma-donor ligands. The clear picture of the M–NHC bond can be better understood by M–NHC pi-interaction. M-L pi interaction is comprised of two steps. One is L → M sigma-donation and M → L π* back bonding. This dative donor nature of NHC and also its behavior in organoselenium is studied through DFT in which it’s optimized structure, bond lengths, molecular vibrations are calculated.

In molecular design techniques, thermodynamic properties are predicted through computational tools. Besides, the simple prediction methods explain the space of molecular design while quantum mechanics can accurately predict the properties without any kind of experimental data; however, it is a bit challenging. Therefore, in this chapter, the significant advancement, demurrers in progression, and the future perspective in designing the chemical compounds via using “computer-aided molecular design” (CAMD) tools will be elucidated. Since the interest in designing novel and advanced compounds is increasing with time, traditional methods are not efficient now. This is the key factor in the advancement of CAMD tools. The work advancement different classes of methods that predict the properties will be explained in the chapter. Applications of CAMD in the single component product designs, mixture designs, and also in integrated product designs will be evaluated. All the difficulties while operating the designs and also in obtaining the results and future perspectives will be reviewed. COSMO-CAMD successfully designs novel promising solvents in the liquid-liquid extraction of phenol from water; therefore, it will be explained thoroughly. Some would debate that theoretical tools in computational chemistry can now come up with eager understandings of any chemical process. Yet, the goblet of effective and reliable prediction of compound reactivity has remained fugitive. Favorably, recent developments in the electronic structure theory, which is based on both concepts, element, and rank-scanty, along with the appearance of the highly sophisticated computer architecture, prominently increased the time and length scales that can be simulated using molecular dynamics. This opens the door for the newly proposed ab initio nanoreactor method. Therefore, ab initio methods will be studied completely because we argue that due to this development in molecular designs, the holy grail of computational discovery for complex chemical reactivity is entirely within our reach.