In designing products, Design-for-Assembly (DFA) has been successfully used for several decades to reduce lead times, processing times, and equipment overhead. Though the DFA approach results in products which are easy and efficient to assemble, such products may be difficult to disassemble and/or may adversely affect the environment. These environmental concerns resulted in the Design-for-Disassembly (DFD) approach, which stresses ease-of-disassembly and environmental compatibility. However, when applied independently of DFA, DFD underestimates the importance of assembly, and consequently can result in increased assembly time and cost. Design-for-Assembly may thus have negative repercussions on disassembly, and vice-versa. Consequently, in order to minimize assembly/disassembly time and cost and maximize component reusability, designers must implement DFA and DFD simultaneously when designing products. In this research, such an approach is developed. The approach, called Concurrent Assembly/Disassembly-Based Design (CAD²), consists of simultaneously selecting joint types and joining processes for products, based upon both assembly and disassembly requirements. Two objectives are considered: the minimization of total assembly/disassembly time or cost. In addition, a ‘penalty score’ measure is developed to quantify the environmental impact (recyclability) associated with any solution. Total enumeration is used to solve these minimization problems. The CAD² approach is demonstrated and evaluated by comparing it with both DFA and DFD for a limited number of cases. The results indicate that the CAD² approach can give better solutions (total time and total cost) than either DFA or DFD. / Master of Science

A methodology for designing mixed model stochastic assembly line systems and a computer package to implement it for realistic problem sizes were developed. The methodology consists of three major steps: (1) generation of feasible sequences of feeding models into the line, (2) generation of feasible allocations (balances) of work elements to work stations, and (3) generation of combinations of sequences and allocations with the best ordering of elements within stations, calculation of total expected cost for each combination, and selection of the one with the least cost. For generating feasible balances, an exhaustive search procedure with a number of heuristic rules was used to ensure searching the whole feasible region in limited time. A cost model based on labor and incompletion costs is used to calculate the cost of each combination, and a recursive procedure to calculate incompletion probabilities for each element and incorporate them into the cost model was implemented. An example problem, its results, and the computer package listings are included. / Master of Science

Viruses have huge impact on controlling diseases and regulating many key ecosystem processes. As metagenomic data can contain many microbiomes including many viruses, by analyzing metagenomic data we can analyze many viruses at the same time. The first step towards analyzing metagenomic data is to identify and quantify viruses present in the data. In order to answer this question, we developed a computational pipeline, FastViromeExplorer. FastViromeExplorer leverages a pseudoalignment based approach, which is faster than the traditional alignment based approach to quickly align millions/billions of reads. Application of FastViromeExplorer on both human gut samples and environmental samples shows that our tool can successfully identify viruses and quantify the abundances of viruses quickly and accurately even for a large data set. As viruses are getting increased attention in recent times, most of the viruses are still unknown or uncategorized. To discover novel viruses from metagenomic data, we developed a computational pipeline named FVE-novel. FVE-novel leverages a hybrid of both reference based and de novo assembly approach to recover novel viruses from metagenomic data. By applying FVE-novel to an ocean metagenome sample, we successfully recovered two novel viruses and two different strains of known phages. Analysis of viral assemblies from metagenomic data reveals that viral assemblies often contain assembly errors like chimeric sequences which means more than one viral genomes are incorrectly assembled together. In order to identify and fix these types of assembly errors, we developed a computational tool called VirChecker. Our tool can identify and fix assembly errors due to chimeric assembly. VirChecker also extends the assembly as much as possible to complete it and then annotates the extended and improved assembly. Application of VirChecker to viral scaffolds collected from an ocean meatgenome sample shows that our tool successfully fixes the assembly errors and extends two novel virus genomes and two strains of known phage genomes. / Doctor of Philosophy / Virus, the most abundant micro-organism on earth has a profound impact on human health and environment. Analyzing metagenomic data for viruses has the beneFIt of analyzing many viruses at a time without the need of cultivating them in the lab environment. Here, in this dissertation, we addressed three research problems of analyzing viruses from metagenomic data. To analyze viruses in metagenomic data, the first question needs to answer is what viruses are there and at what quantity. To answer this question, we developed a computational pipeline, FastViromeExplorer. Our tool can identify viruses from metagenomic data and quantify the abundances of viruses present in the data quickly and accurately even for a large data set. To recover novel virus genomes from metagenomic data, we developed a computational pipeline named FVE-novel. By applying FVE-novel to an ocean metagenome sample, we successfully recovered two novel viruses and two strains of known phages. Examination of viral assemblies from metagenomic data reveals that due to the complex nature of metagenome data, viral assemblies often contain assembly errors and are incomplete. To solve this problem, we developed a computational pipeline, named VirChecker, to polish, extend and annotate viral assemblies. Application of VirChecker to virus genomes recovered from an ocean metagenome sample shows that our tool successfully extended and completed those virus genomes.

Yes / Sequential ring-opening and reversible addition–fragmentation chain transfer (RAFT) polymerization was used to form a triblock copolymer of tetrahydropyran acrylate (THPA), 5-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC) and L-lactide. Concurrent deprotection of the THPA block and crystallization-driven self-assembly (CDSA) was undertaken and allowed for the formation of cylindrical micelles bearing allyl handles in a short outer core segment. These handles were further functionalized by different thiols using photo-initiated thiol–ene radical reactions to demonstrate that the incorporation of an amorphous PMAC block within the core does not disrupt CDSA and can be used to load the cylindrical nanoparticles with cargo. / Royal Society (Great Britain), Engineering and Physical Sciences Research Council (EPSRC), European Research Council (ERC)

No

The understanding of self-assembly processes is important for fabrication of well-defined structures with new functionalities for applications in the area of biomedical sciences, material sciences and electronics. In this thesis, two types of self-assembly processes are described: (1) self-assembly of fullerene derivatives in water and (2) self-assembly on surfaces using layer-by-layer (LbL) approach. The various interactions and parameters involved in the self-assembly are detailed in the introductory chapter 1. The various internal parameters like molecular geometry, intramolecular and intermolecular forces that guides the self-assembly process of amphiphiles in water are discussed. The experimental procedures used in the present thesis for the fabrication of nanostructures via self-assembly approach are also described. In the later part of the chapter, the LbL technique for fabrication of thin films and microcapsules is reviewed where various interactions involved in the growth of LbL assembly are discussed. The effect of ionic strength and pH on the growth and property of LbL assemblies is elaborated. A brief discussion of the materials used in the thesis ‒ fullerene, bovine serum albumin (BSA) and nanocrystalline cellulose (NCC) is also provided The self-assembly behaviour of amphiphilic fullerene derivatives are described in chapter 2. Fullerene is anisotropically substituted with five polar hydroxyl groups using organo-copper reagent. The derivative can interact in water via the van der Waals and hydrophobic interactions of the fullerene moiety as well as the intermolecular hydrogen bonding among the hydroxyl groups and also with water. The penta-hydroxy fullerene derivative self-assembles in water as vesicular structures. The size of these vesicles can be varied by modifying the kinetics of self-assembly which was done by changing the rate of addition of non-solvent (water) to the solution of the fullerene derivative. In the second derivative, the hydroxyl groups are substituted with less polar methoxy groups. The penta-methoxy fullerene derivative cannot participate in inter-molecular hydrogen bonding formation unlike the penta-hydroxy derivative but there is possibility of hydrogen bond formation with water where oxygens on methoxy group can act as hydrogen bond acceptor. The penta-methoxy fullerene does not show any vesicle formation in water. The computational simulation studies were carried out on the two fullerene derivatives to understand the self-assembly behaviour of these two derivatives. Furthermore, the vesicle structures formed by the penta-hydroxy fullerene derivative are used for entrapment of hydrophobic polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and also hydrophilic dye, Rhodamine B. In both the cases, fluorescence quenching is observed due to electron transfer reaction with fullerene and hence these fullerene vesicles can be used to study the effect of confinement on electron transfer reactions and other chemical dynamics. The layer-by-layer self-assembly approach for the fabrication of biopolymeric thin films and microcapsules is discussed in the chapters 3 to 6. The biocompatible nanoparticles and nanofibers were used as the components of the assembly. In chapter 3, we have described fabrication of thin film of bovine serum albumin (BSA) nanoparticles via LbL approach using biopolymer chitosan as the complementary polymer. The driving force for the assembly growth of the assembly was the electrostatic and complementary hydrogen bond formation between the two components. The idea of incorporating nanoparticles in the thin film was that the nanoparticles can act as reservoirs for functional materials. The films were loaded with anticancer drug doxorubicin and show pH dependent release of the drug. The various interactions involved in the LbL assembly of BSA nanoparticles and polymers were investigated towards understanding the growth mechanism of the assembly in chapter 4. The understanding of the interactions involved in the assembly formation is important in order to modify the conditions of the assembly for enhancing the growth. It is inferred from the study reported in this chapter that not only the interaction of nanoparticles with polymers but also the inter-particle interactions are important factors in determining the growth of LbL assembly of nanoparticles/polymers. The growth of the assembly is enhanced on minimizing the inter-particle repulsions, which was achieved in case of BSA nanoparticles by modifying the pH of the assembly. We also utilized the LbL self-assembly approach for the delivery of lipophilic drugs. The lipophilic drugs are difficult to administer in the body due to their poor water solubility and hence show poor pharmacokinetic profile. The methods for incorporating hydrophobic drugs in LbL assembled thin films and microcapsules are described in chapters 5 and 6. In chapter 5, hydrophobic molecules binding property of albumin has been exploited for solubilisation of a water-insoluble molecule, pyrene (model drug) and hydrophobic drug, curcumin, by preparation of non-covalent conjugates with BSA. The interaction with BSA provided negative zeta potential to the previously uncharged molecules and hence they can be incorporated in the LbL assembled thin films and microcapsules using electrostatic as well as hydrogen bonding interaction with biopolymer, chitosan. The fabrication of protein encapsulated stable microcapsules with hydrophobic molecules incorporated in the shell of the microcapsules has also been demonstrated. The microcapsules were further capable of loading hydrophilic molecules like Rhodamine B. Thus, this approach can be employed for fabrication of multi-agent carrier for hydrophobic and hydrophilic drugs as well as therapeutic macromolecules. In chapter 6, we have incorporated nanocrystalline cellulose (NCC) LbL assembled thin films and microcapsules. The assembly formed was porous in nature due to the nano-fibrous morphology of NCC. The nanoassemblies can act as potential drug delivery carrier, which has been demonstrated by loading anticancer drug doxorubicin, and a lipophilic drug, curcumin. Doxorubicin hydrochloride, the salt form of the drug, doxorubicin, has good water solubility and hence can be postloaded in the assembly by diffusion from its aqueous solution. In the case of curcumin, which has limited solubility in water, a stable aqueous dispersion of the drug was prepared via noncovalent interaction with NCC prior to incorporation in the LbL assembly. The interaction of various other lipophilic drugs with NCC was analysed computationally.

The global competitive environment and the growing demand for personalised products have increased the interest of companies in producing similar product models on the same assembly line. Companies are forced to make significant structural changes to rapidly respond to diversified demands and convert their existing single-model lines into mixed-model lines in order to avoid unnecessary new line construction cost for each new product model. Mixed-model assembly lines play a key role in increasing productivity without compromising quality for manufacturing enterprises. The literature is extensive on assembling small-sized products in an intermixed sequence and assembling large-sized products in large volumes on single-model lines. However, a mixed-model parallel two-sided line system, where two or more similar products or similar models of a large-sized product are assembled on each of the parallel two-sided lines in an intermixed sequence, has not been of interest to academia so far. Moreover, taking model sequencing problem into consideration on a mixed-model parallel two-sided line system is a novel research topic in this domain. Within this context, the problem of simultaneous balancing and sequencing of mixed-model parallel two-sided lines is defined and described using illustrative examples for the first time in the literature. The mathematical model of the problem is also developed to exhibit the main characteristics of the problem and to explore the logic underlying the algorithms developed. The benefits of utilising multi-line stations between two adjacent lines are discussed and numerical examples are provided. An agent-based ant colony optimisation algorithm (called ABACO) is developed to obtain a generic solution that conforms to any model sequence and it is enhanced step-by-step to increase the quality of the solutions obtained. Then, the algorithm is modified with the integration of a model sequencing procedure (where the modified version is called ABACO/S) to balance lines by tracking the product model changes on each workstation in a complex production environment where each of the parallel lines may a have different cycle time. Finally, a genetic algorithm based model sequencing mechanism is integrated to the algorithm to increase the robustness of the obtained solutions. Computational tests are performed using test cases to observe the performances of the developed algorithms. Statistical tests are conducted through obtained results and test results establish that balancing mixed-model parallel two-sided lines together has a significant effect on the sought performance measures (a weighted summation of line length and the number of workstations) in comparison with balancing those lines separately. Another important finding of the research is that considering model sequencing problem along with the line balancing problem helps algorithm find better line balances with better performance measures. The results also indicate that the developed ABACO and ABACO/S algorithms outperform other test heuristics commonly used in the literature in solving various line balancing problems; and integrating a genetic algorithm based model sequencing mechanism into ABACO/S helps the algorithm find better solutions with less amount of computational effort.

Metallic nanoparticles are unique materials for optical, electronic, catalytic, and sensing applications. Due to the vast flexibility in controlling the surface chemistry of these particles through functionalization there is a great deal of interest in using metallic nanoparticles as building blocks in the development of more complex nanostructures through the use of a 'bottom-up' approach. Using self assembly techniques, one can exploit spontaneous chemical interactions to build complex constructs on the nanometer scale. Towards this end, gold nanorods have been synthesized and modified with various polymers, inorganic oxides and organic ligands to establish principles for self-assembly of these unique nanomaterials. Gold nanorods are of great interest due to their strong optical absorption in the visible and near infrared regions, which can be tuned through material preparation and modification of the surrounding environment. This thesis focuses on investigating approaches for both irreversible and reversible self-assembly of gold nanorods. Techniques such as dynamic light scattering (DLS), ultraviolet-visible (UV) spectroscopy, transmission electron microscopy (TEM), and polarization modulation infrared reflection absorbance spectroscopy (PM-IRRAS) were used to characterize the colloidal particles and gold surfaces. A novel contribution of this work is the successful demonstration of end-to-end linking of gold nanorods in a rapid and reversible manner using a pH responsive polypeptide.

Fokus i detta arbete ligger i att konstruera om vissa delar av produkten för lättare och snabbare montering. Huvudproblemen som upptäcks i detta arbete handlar om skymd sikten vid monteringen samt bristande utrymme för installation av komponenter. Arbetet börjar med att formulera undersökningsproblemet och sedan presenteras olika vetenskapliga metoder, relevanta teorier samt genomförandet av arbetet. Nulägesbeskrivning, nulägesanalys samt förbättringsförslag till problemen utförs i genomförandet. På grund av att ingen egen tillverkning sker på företaget har författarna valt att utföra beräkningar istället för att verifiera att lösningarna till problem håller. Resultatet i detta arbete blir att antalet delar och skruvar har minskats samt att sikten och tillgängligheten vid insättning av komponenter har förbättrats, vilket kommer att minska monteringstiden till en viss del.

Self–assembly has long been attracting chemists’ attention because it can yield fascinating supramolecular architectures in a single step. More precisely, metal–ligand coordination–driven self–assembly has stood out as an efficient methodology in this paradigm due to simple design principle and high predictability of the final molecular architectures. Moreover, one can envisage hierarchical nanoscopic molecular architectures with a vast range of size, shape and functionality via this methodology. Two–component self–assembly (involving one type of donor and one type of acceptor) is relatively easy to monitor and a widely used protocol. Whereas, multicomponent self–assembly (involving more than one types of donors/or acceptors) is too complex due to the possibility of formation of several products. The prime advantage of multicomponent self–assembly lies in one–pot construction of topologically complicated multifunctional architectures. Template– induced multicomponent self–assembly of discrete architectures is recently investigated to some extent. But, template–free multicomponent self–assembly of discrete architectures is rare in the literature. Physico–chemical property of a self–assembled product is coded in the functional groups present in its precursor building units. Functional supramolecular architectures have important applications in many potential fields such as chemosensing, drug delivery, supramolecular catalysis, etc. Porphyrin, pyrazole, imidazole, etc. functionalized organic molecules are hydrophilic as well as hydrophobic in nature. Introduction of such functionality in building units can lead to amphiphilic supramolecular complexes. Therefore, such complexes can be employed as hosts for versatile guests, or as molecular reactors for various chemical reactions. In general, counter ions block the cavity of ionic molecular architectures. Thus, when ionic molecular architectures are employed as hosts, they cannot fully provide their cavity towards guest molecules. In contrast, neutral molecular complexes are expected to be better hosts. It is well known that alkenyl/alkynyl heavy metal complexes exhibit efficient chemoluminescence due to facile metal to ligand charge transfer (MLCT). Hence, such complexes can be employed as efficient chemosensors towards the detection of electron deficient molecules such as nitroaromatics which are the chemical signatures of many powerful explosives. In these regards, a considerable effort is being paid recently to design and construct various functional supramolecular architectures. Symmetry and rigidity of building units increase predictability of the final product in self– assembly. In this regard, symmetric; rigid Pd(II)/Pt(II)–based acceptors and polypyridyl donors are explored extensively in metal–ligand coordination–driven self–assembly. In contrast to rigidity, flexibility endows building units to adopt thermodynamically most stable conformer/architecture. Hence, same set of building units can render different conformers/architectures in presence of different templates for the sake of suitable host–guest interactions. Contrary to high symmetry, asymmetry in building units leads to molecular architectures with polar environments. But, due to the possibility of formation of several isomeric products from the self–assembly involving such building units, it is difficult to monitor the reaction and purify the products. Hence, designing appropriate synthetic routes which can lead to formation of single isomeric products possessing flexible/asymmetric building units is a challenge to synthetic chemists. Investigations incorporated in the present thesis are focused to design and construct various 2D/3D discrete supramolecular architectures employing self–assembly of mainly Pd(II)/Pt(II) acceptors with N/O donors. Elemental analyses, IR/NMR/UV–Vis/fluorescence/mass spectroscopy and single crystal X–ray diffraction analysis are among prime techniques employed for characterization of the reported architectures. For a few cases, powder X–ray diffraction (PXRD) analysis and density functional theory (DFT) calculations are also carried out. CHAPTER 1 of the thesis provides a brief general introduction to self–assembly and supramolecular chemistry. It emphasizes on the metal–ligand coordination–driven self–assembly approach towards the construction of a library of 2D/3D supramolecular architectures. CHAPTER 2 describes formation of a series of template–induced and template–free discrete 3D Pd(II) molecular prisms via multicomponent self–assembly. Because of the possibility of formation of several products, multicomponent self–assembly is difficult to monitor. For example, several molecular architectures are expected from a three–component self–assembly involving a 90° acceptor [ca. cis–blocked Pd(II)], a 120° tritopic donor [ca. benzene–1,3,5– tricaboxylate (tma)] and a 180° donor [ca. 4,4'–bipyridine (4,4'–bpy) or pyrazine (pz)]. Interestingly, treatment of cis–(tmen)Pd(NO3)2 [tmen = N,N,N′,N′–tetramethylethylenediamine] with 4,4'–bpy and K3tma in 6 : 3 : 2 molar ratio at room temperature resulted in mainly a nanoscopic molecular trigonal prism [{(tmen)Pd}6(bpy)3(tma)2](NO3)6 (1) with three 4,4'–bpy pillars, two tma caps and six cis–(tmen)Pd connectors (Scheme 1). Scheme 1: Schematic representation of the formation of multicomponent self–assembled molecular trigonal prisms 1, 2 and 3. Surprisingly, the same reaction in presence of benzene–1,3,5–tricaboxylic acid (H3tma) as guest yielded exclusively the guest–encapsulated analogous molecular prism [{(tmen)Pd}6(bpy)3(tma)2(H3tma)2](NO3)6 (2; Scheme 1). It is also presented how variation of steric crowding at connectors (acceptors) influenced final outcomes. Self–assembly of cis– (en)Pd(NO3)2 [en = ethylenediamine] with 4,4'–bpy and K3tma in 6 : 3 : 2 molar ratio at room temperature resulted in a triply interlocked nanoscopic 3D coordination cage [{(en)Pd}6(bpy)3(tma)2]2(NO3)12 (3; Scheme 1). It is also shown that above trend is followed even upon changing the pillar length from 4,4'–bpy to pz. Aromatic –stacking interactions amog tma caps as well as among 4,4'–bpy pillars provided considerable stability to interlocked archirecture 3. Steric crowding due to the methyl groups in cis–(tmen)Pd connectors hindered intercalation and hence led to non–interlocked architecture 1. As expected, similar self–assembly using moderately crowded acceptor cis–(pn)Pd(NO3)2 [pn = 1,2–diaminopropane] with same donors 4,4'–bpy and K3tma resulted in a mixture of analogous triply interlocked and non– interlocked architectures in solution though it was found to be only triply interlocked architecture in solid state. Interestingly, irrespective of the steric crowding of the blocking amines, self– assembly in presence of H3tma as guest preferred exclusive formation of guest–encapsulated prisms of type 2 (Scheme 1). This is due to considerable stabilazation via aromatic –stacking interactions amog tma caps and H3tma guests. Formation of guest–free discrete molecular prisms (such as 1) and triply interlocked coordination cages (such as 3) were confirmed by spectroscopic and single crystal X–ray diffraction analyses. Whereas, formation of guest– encapsulated discrete molecular prisms (such as 2) was established by DOSY, ROESY 2D NMR spectroscpic study in conjunction with energy optimized geometry analysis. CHAPTER 3 reports design and syntheses of a series of porphyrin functionalized nanoscopic 3D molecular open prisms. Self–assembly of a C4 –symmetric tetratopic donor with a 90° ditopic acceptor can, in principle, lead to several architectures such as trigonal; tetragonal; pentagonal; hexagonal; etc. open prisms, closed cube or 1D oligomers. Both of 1,5,10,15–tetrakis(4– 12 pyridyl)porphyrin (L) and 1,5,10,15–tetrakis(3–pyridyl)porphyrin (L) possess pseudo C4 – 1 symmetry. Surprisingly, treatment of Lwith the 90° ditopic acceptor cis–(dppf)Pt(OTf)2 [dppf = diphenylphosphinoferrocene, OTf = trifluoromethanesulphonate] yielded exclusively an 1 unprecedented [6 + 12] self–assembled hexagonal open prism [(dppf)12Pt12L6](OTf)24 (4; Scheme 2). Scheme 2: Schematic representation of formation of [6 + 12] self–assembled molecular hexagonal open prism 4 and its Zn(II) embedded complex 4a. 2 In contrast, [3 + 6] self–assembled trigonal open prisms are adopted upon self–assembly of Lwith Pd(II)–based 90° ditopic acceptors. These complexes show facile incorporation of Zn(II) ions into porphyrin N4 –pockets. Moreover, they incorporate high microporosity in solid state and they are amphiphilic in nature due to porphyrin functionality. One of the trigonal open prisms revealed its considerably high adsorbate–adsorbent affinity towards non–polar gas such as N2 and protic solvent vapors such as water, methanol and ethanol. Formation of hexagonal and trigonal open prisms is fully authenticated by spectroscopic and single crystal X–ray diffraction analyses. CHAPTER 4 describes design and synthesis of a pyrazole functionalized flexible donor (L) and its self–assembly towards the construction of three nanoscopic 3D supramolecular discrete cages 5–7 (Scheme 3). Scheme 3: Schematic representation of formation of [4 + 6] self–assembled molecular double–square 5 and [2 + 3] self–assembled molecular trigonal bipyramids 6–7. 3 Due to flexibility, Lcan adopt different conformations and hence several isomeric architectures 3 are expected upon self–assembly. For example, self–assembly of Lwith a rigid ditopic 90° acceptor can lead to trigonal bipyramid (TBP), double–square, adamantanoid or truncated 3 tetrahedron. Treatment of Lwith cis–(tmen)Pd(NO3)2 yielded a [4 + 6] self–assembled double–3 square [(tmen)6Pd6L4](NO3)12 (5; Scheme 3). Much to our surprise, replacement of cis– (tmen)Pd(NO3)2 with CuCl2 or AgOTf yielded [2 + 3] self–assembled molecular TBP 33 [Cu3Cl6L2] (6) or [Ag3L2](OTf)3 (7), respectively (Scheme 3). CHAPTER 5 presents study of self–assembly involving flexible asymmetric donors and rigid 4 symmetric 90° acceptors. Three ambidentate donors 5–pyrimidinecarboxylate (L), nicotinate–56 N–oxide (L) and isonicotinate–N–oxide (L) were employed in self–assembly with symmetric rigid 90° acceptors cis–(dppf)M(OTf)2 [M = Pd(II)/Pt(II)]. Due to flexibility and different 464 connectivity of these donors L–L, several linkage isomers are expected. Treatment of Lwith cis–(dppf)M(OTf)2 in 1 : 1 molar ratio resulted in exclusive formation of single linkage isomeric 4 [3 + 3] self–assembled symmetric molecular triangles [(dppf)3M3L3](OTf)3 (8: M = Pd and 9: M = Pt), where the donors connected to metal centers in head–to–tailfashion (Scheme 4). Similar 56 reactions of Land Lwith cis–(dppf)M(OTf)2 resulted in self–sorting of [2 + 2] self–assembled molecular rhomboids 10–13 (Scheme 4). Exclusive self–selection of single linkage isomeric architectures 8, 9, 10 and 12 was fully established by spectroscopic as well as single crystal X– ray diffraction analyses. Though we could not obtain suitable X–ray diffraction quality single crystals of 11 and 13, exclusive formation of single isomeric [2 + 2] self–assembled rhomboids 131 was established by multinuclear NMR (H and P) in conjunction with ESI–MS spectroscopic studies. Scheme 4: Schematic representation of formation of complexes 8–13. Part A of the CHAPTER 6 describes how two neutral organometallic mononuclear chelates are formed upon treatment of disodium fumarate (,–unsaturated dicarboxylate) with cis– (dppf)Pd/Pt(OTf)2 at ambient conditions. Reaction of 90acceptors cis–(dppf)Pd/Pt(OTf)2 with fumarate is expected to result in [4 + 4] self–sorted molecular squares/or [2 + 2] self–sorted molecular rhomboids (Scheme 5). To our surprise, the above reactions led to an unusual reduction of C–C double bond followed by concomitant formation of mononuclear chelates [M(dppf)(C4H4O4)] (M = Pd for 14 and Pt for 15) via coordination with one of the carboxylate oxygen atoms and –carbon to metal centers (Scheme 5). Scheme 5: Schematic representation of formation of the complexes 14–15. Part B of the CHAPTER 6 describes design and synthesis of a novel shape selective “clip” 1 shaped bimetallic Pd(II) acceptor Mand its self–assembly with disodium fumarate to construct a neutral tetrametallic Pd(II) supramolecular rectangle 16 (Scheme 6, left). Similarly, a shape selective 180° bimetallic Pd(II) acceptor was also synthesized and employed in self–assembly with several “clip” shaped organic donors to achieve several cationic tetrametallic Pd(II) supramolecular rectangles. Scheme 6: Schematic representation of the formation of neutral Pd4 (left) and Pd2 (right) molecular rectangles. Moreover, synthesis of a neutral bimetallic Pd(II) molecular rectangle 17 via one–pot reaction of trans–(PEt3)2PdCl2 with 1,8–diethynylanthracene (Scheme 6, right) is also presented herein. These –electron rich rectangles exhibit prominent chemoluminescence. Chemosensitivity of these complexes towards the detection of electron deficient nitroaromatics via fluorescence study is also discussed in details in this section. (Pl refer the abstract file for figures).