Sharif Digital Repository

In the first part, two copper(I) complexes were synthesized as additive products of nitrogen-donor, phosphine and stibine ligands and copper(I) iodide, and in the second part, the triple-core copper(I) complex was synthesized with a phosphine ligand. The synthesized complexes were identified by FT-IR, 1H-NMR, 31P-NMR spectroscopy and the structure of these complexes was investigated using single crystal X-ray diffraction. In addition, the possibility of Cuprophilic interactions using structural parameters, And theoretical studies were reviewed. On the other hand, molecular structure determination allowed us to fully investigate the intramolecular and intermolecular interactions of the... 

Tropical algebraic geometry is a fairly new branch in geometry which is called so in honor of Brazilian mathematician Imre Simon who was pioneer of this field.The set equipped with the addition and multiplication is a semifield.Algebraic geometry objects like algebraic varieties can be defined over.Polynomials and rational functions are defined over.The functions that they define are piecewise linear and concave functions and the set of points where they are nonlinear is a tropical variety which is a concave polyhedral. Thus, tropical algebraic geometry is a piecewise linear version of algebraic geometry.Another approach to tropical algebraic geometry comes back to the works of Russian... 

Descriptive complexity refers to the difficulty of expressing a problem in a formal language, allowing for a complete and precise description of the problem, including output specifications for function problems. Despite the success of the descriptive approach in computational complexity, this approach has been predominantly used for decision problems. In contrast to decision problems, a counting problem can be considered as a function with the range of natural numbers. This thesis focuses on the examination of counting problems from a descriptive perspective, exploring the connection between their descriptive and computational versions. Toward this goal, weighted logic is utilized to... 

In general, Constrain Satisfaction Problems (CSP’s) are NP-complete, however, this is not the case, if we impose some restrictions on the constraints. Due to importance and applications of CSP’s in different areas of engineering and science including artificial intelligence, relational databases and logic, investigating the computational complexity of CSP’s is an important issue. Computational complexity of CSP’s has been investigated from a variety of aspects, including the Universal Algebraic approach that has given rise to a solution of dichotomy conjecture recently. In this thesis based on contributions of Bulatov, Krokhin and Jeavons, we try to explain this universal algebraic approach... 

Nowadays Systems in different fields of research like computer science, biology, social networks, information networks, and economics are modeled as graphs. The graphs which model real world systems have very different topological characteristics than those of classic networks. One of the prominent characteristics of these networks, is that its not practical to describe a general model for their structure and behavior. As a consequence of this complexity in modeling and structure, these networks are called complex networks. One of the most important observations in complex networks is the presence of communities, it means that in such networks one can separate vertices in disjoint sets, such... 

In the current study, the dinuclear copper(I) complex ,[Cu2(μ-phthalazine)(phthalazine)2(μ-dppm)2](PF6)2,(1), has been prepared by the reaction of two equiv of [Cu(CH3CN)4]PF6, three aquiv of phthalazine, and two equiv of bis(diphenylphosphino)methane (dppm). However a mixture of two four coordinated copper(I) complex,1, and a three and four-coordinated copper(I) complex ,[Cu2(μ-phthalazine)(phthalazine)(μ-dppm)2](PF6)2,(2), have been prepared when the reaction has been carried out with equal ratio of the reactants. The structure of 1 and 2 determined using. X-ray crystallography in solid state and the structure of 1, further characterized by multinuclear NMR spectroscopy in solution.... 

Studying of synthetic models which have many similarities to Oxygen Evolving Complex (OEC) in Photosystem II (PS II) can play a very significant role in gaining an insight to mechanism of oxidation of water in PS II. The aim of this study is to investigate the mechanistic and kinetic aspects of oxidation of dopamine as an important neurotransmitter in body by tri and tetranuclear oxo-bridge manganese clusters which have been reported in the past to get some information about the influence of protonation and deprotonation of oxo-bridges and water molecules bonded to these clusters on properties of them in redox reactions.In aqueous media, the trinuclear complex... 

Epoxidation of alkenes by Mn(III)meso-tetra(4-sulfonatophenyl)porphyrin chloride (MnTPPS4Cl) in the various homogeneous and heterogeneous catalytic systems was investigated. In the case of homogeneous catalysis, epoxidation of cyclooctene in CH2Cl2/MeOH mixture using urea hydrogen peroxide (UHP) as an oxidant and imidazole as a co-catalyst results in the formation of cycloocetene oxide in 87% yield. Using this catalytic system various alkenes successfully oxidized to their corresponding epoxide in high conversions and selectivity. Cyclic alkenes oxidized more easily than linear alkenes. In addition, epoxidation of alkenes was investigated in the heterogeneous catalytic systems. For this... 

Antioxidants are compounds with anti-cancer, anti-bacterial, anti-viral, anti-aging and anti-allergic properties. In the present study, a quantum mechanical approach has been used to shed light on the presence effect of glycoside group on the antioxidant ability of chrysin as one of the most important consumable flavonoids and two glycoside derivatives, chrysin-6-C-fucopyranoside and chrysin-3-malonyl-6-C-fucopyranoside which has electron-withdrawing group (EWG) in its C3 of glycoside group. Density functional theory (DFT) using B3LYP and UB3LYP functional and split-valance 6-311++G ** basis set were used to optimize chrysin, its different derivatives, and their radicals. Analysis of... 

Application of convolution-based transforms such as Fourier transform and wavelet transform are among the widely-used approaches in structural identification problems. These methods, however, are mostly based on a classical damping model for the structures. Hence, such methods cannot be used to accurately identify the modal properties of non-classically damped systems, such as structures equipped with energy dissipated devices, base isolated and multi-segment structures. In this study, complex-valued wavelet transform is used to identify the dynamic properties of structures with arbitrary damping models. This method is known to be able to identify the modal properties of highly damped... 

A number of questions from a variety of areas of mathematics lead one to the problem of analyzing the topology of a simplicial complex. However, there are few general techniques available to aid us in this study. On the other hand, some very general theories have been developed for the study of smooth manifolds. One of the most powerful, and useful, of these theories is Morse Theory. We present a combinatorial adaptation of Morse Theory, which we call discrete Morse theory that may be applied to any simplicial complex (or more general cell complex). Our goal is to present an overview of the subject of discrete Morse Theory that is sufficient both to understand the major applications of the... 

Two new dioxomolybdenum(VI) complexes have been synthesized by the reaction of N,N'-bis(5-chlorosalicylidene)-2,2'-dimethyl-1,3-propanediamine and N,N'-bis(5-bromosalicylidene)-2,2'-dimethyl-1,3-propanediamine as Schiff base ligands with [Mo(O)2(acac)2] in methanolic solution.and their electronic structures have been investigaged theoretically. The Schiff base ligands H2L1 and H2L2 were prepared by reaction of 5-Chlorosalicylaldehyde and 5-Bromosalicylaldehyde with 2,2'-dimethyl-1,3-propanediamine, respectively. The result of these reactions, was two complexes of Mo(O)2L1 and Mo(O)2L2 .The compounds were characterized by elemental analyses (CHN), and 1HNMR and IR spectroscopic techniques.... 

In most radio receivers like superheterodyne receivers, a weak desired incoming signal is accompanied with many interferer signals that are much more powerful than the desired signal itself. These interferers, also called blockers, can cause a great disturbance in the functionality of the receiver. Due to gain compression and an increase in the noise figure (NF) of the receiver, the blockers should be filtered before the arrival at the output of the LNA. Because of the low quality factors of the available on chip inductors and in order to eliminate the out of band interferer signals and image frequency (in superheterodyne receivers), usually an external surface acoustic wave (SAW) filter is... 

The cationic cyclometalated platinum(II) complex [Pt(ⱪ2-2-ppy)(ⱪ1-N-2-ppy)2][OTF], 2, has been prepared by reaction of [PtMe3I]4, 1, with one equiv Ag(OTF) and then three equiv 2-phenylpyridine. The similar complex with formula [Pt(ⱪ2-p′py)(ⱪ1-N-p′py)2][OTF], in which p′py = 2-(3-bromophenyl)pyridine, 4, has been prepared with similar procedure, from the reaction of 1 with one equiv Ag(OTF) and then three equiv of the corresponding cyclometalating ligand. Also, the cationic cyclometalated platinum(IV) complex [Pt(2-(p-tolyl)pyridine)2(Me)(H2O)][OTF], 3, has been prepared from the reaction of 1 with one equiv Ag(OTF) and then three equiv 2-(p-tolyl)pyridine. The structure of complexes 2, 3... 

Complex networks science have become the major method in the modeling of topological features of networks and graphs. Although file sharing Peer-to-Peer systems can be modeled by networks with un-weighted nodes and links, using these networks for Peer-to-Peer streaming systems have not led to a suitable model.In this research, we aim to model Peer-to-Peer streaming networks with weighted nodes and weighted links so that present the performance of nodes and the amount of streaming that is transmitted between nodes respectively. Due to lack of information about upload bandwidth distribution in networks we assume this distribution as uniform. Because of dynamics of network, this distribution... 

Secure multi-party computation (MPC) enables a group of mutually distrustful parties to compute a joint and agreed upon function of their private inputs without disclosing anything but the corresponding output. One of the most important secure computation protocols is private set intersection (PSI). In PSI, often two or several parties wish to find the intersection of their sets without revealing other non-common elements. There exist some other variants of PSI protocol like PSI cardinality or threshold PSI which in the former only the cardinality of the intersection set is revealed and in the latter the intersection set is revealed if its cardinality is greater (less) than a certain value.... 

The cyclometalated platinum(II) complex [Pt(Me)(bhq)(2-vpy)], 2, in which bhq = benzo{h}quinolone, 2-vpy = 2-vinylpyridine, has been prepared by reaction of the cyclometalated complex [Pt(Me) bhq)(SMe2)], 1 with one equiv 2-vinylpyridine. The similar complex [Pt(p-tolyl)(ppy)(2-vpy)], 3 in which ppy = 2-phenyl pyridine, has been prepared from reaction of the platinum(II) complex cis-[Pt(p-MeC6H4)2(SMe2)2] with one equiv 2-phenylpyridine and one equiv 2-vinylpyridine. Reaction of 2 with one equiv Br2 in acetone gave the cyclometalated platinum(IV) complex [Pt(bhq)Me(Br)(NC5H4CHCH2Br)], 4. The structure of the complexes 1-3 were determined using NMR Spectroscopy. The crystal structure of 3... 

Considerable effort has been directed in recent years towards the transition metal complex catalyzed oxidation of organic compounds. Herein the synthsis of the iron complex of bis(oxazoline) ligand as a novel catalyst is reported, and the catalytic activity of this complex in oxidation of sulfides is investigated. Bis(2-oxazolynil)methane as ligand is prepared by condensation of diethylmalonate with 2-aminoethanole in 1:2 molar ratio and finally corresponding complex is synthesized by the reaction between FeCl3.6H2O and Bis(2-Oxazolynil)methane in 1:1 molar ratio. The complex is characterized by using IR, UV-Vis, cyclic voltametery, conductometery and elemental analysis data. Moreover,... 

In this thesis, we first briefly review the basic concepts of stochastic processes. After reviewing and studying the dynamic equation that can explain a stochastic process, we show how one can find on a data-driven basis, the first-, second- and higher-order interactions between different subunits of a complex system by disentangling the dynamics of multivariate time series into stochastic and deterministic parts. Our data-driven approach is to detect different degrees of interactions obtained using conditional moments of Kramers-Moyal coefficients from unconditioned correlation functions and statistical moments of multivariate N-dimensional multivariate time series. Finally, we study the... 

Complex networks science have received tremendous attention in recent years and the brain is one of the systems to which graph theoretical tools have been applied. Alzheimer’s disease (AD) is a neurodegenerative disease affecting many of elderly population. AD changes the anatomy of the brain, which subsequently results in changes in its functions. These changes have been frequently reported in signals recorded from the brain (such as MEG, fMRI and EEG). Among these neuroimaging techniques EEG is one of the most aproprate methods for extracting functional connectivites according to high temporal resolution. In this thesis, we aimed at analyzing the properties of EEG-based functional networks...