INTRODUCTION CURRENTLY, THE PHOSPHORAMIDATES CHEMISTRY IS OF GREAT INTEREST DUE TO ITS WIDE APPLICATIONS IN VARIOUS AREAS OF SCIENCE [1, 2]. THERE HAVE BEEN MANY EFFORTS FOR THE SYNTHESIS, CHARACTERIZATION AND STRUCTURAL INVESTIGATIONS ON THESE COMPOUNDS [3, 4]. THE QUANTUM CHEMICAL COMPUTATIONS WERE CONDUCTED ON PHOSPHORAMIDATES TO PREDICT THEIR STRUCTUREAL PARAMETERS AND TO COMPARE THE CALCULATED RESULTS WITH THE EXPERIMENTAL ONES [5, 6].COMPUTATIONAL DETAILS THE STRUCTURE OF A NEW PHOSPHORIC TRIAMIDE WITH FORMUAL 4-CH3-C6H4S (O) 2NHP (O) (NHCH2C4H5) 2 WAS OPTIMIZED IN THE GAS PHASE USING GAUSSIAN 98 PROGRAM [7] AT DFT (B3LYP AND B3PW91) LEVEL OF THEORY WITH STANDARD 6-31+G** BASIS SET. THE NATURAL BOND ORBITAL (NBO) CALCULATIONS WERE PERFORMED TO OBTAIN THE ATOMIC HYBDIDIZATIONS.

NICOTINAMIDE, WHICH IS ESSENTIAL FOR THE HUMAN BODY, PLAYS A CRUCIAL ROLE IN BIOLOGICAL OXIDATIVE CHEMISTRY [1]. VARIOUS COMPLEXES OF THIS AMIDE HAVE BEEN STUDIED WITH SEVERAL METALS SUCH AS CO (II), CU( II), NI(II), ZN (II), AG(I) [2, 3]. PHOSPHORAMIDES INCLUDING -C(O)N(H)P(O)- MOIETY HAVE BEEN USED AS O-DONOR LIGANDS IN THE REACTION WITH DIFFERENT METAL IONS [4,5]. HEREIN WE CHOSE A PHOSPHORIC TRIAMIDE CONTAINING N-NICOTINYL GROUP, WITH FORMULA C5H4NC(O)NHP(O)[NHC(CH3)3]2, WHICH HAVE 3 SUITABLE DONOR SITES TO COORDINATE WITH METAL IONS. NEW HG(II) COMPLEX OF THIS LIGAND WAS SYNTHESIZED FROM THE REACTION OF HGCL2 AND LIGAND IN HOT ETHANOL AND WAS CRYSTALLIZED FROM ITS SOLUTION IN ETHANOL/CHLOROFORM MIXTURE AT ROOM TEMPERATURE. THEN IT WAS FULLY CHARACTERIZED BY 1H, 13C, 31P NMR, IR, UV-VIS SPECTROSCOPY AND ELEMENTAL ANALYSIS AND ITS CRYSTAL STRUCTURE WAS DETERMINED BY X-RAY CRYSTALLOGRAPHY. STRUCTURAL RESULTS SHOWED THAT IN THIS COMPLEX EACH LIGAND ACTS AS A BRIDGE BETWEEN TWO HG. IT IS COORDINATED TO ONE HG VIA ITS C=O SITE AND TO ANOTHER FROM THE NITROGEN OF ITS PYRIDINE RING. THE BOND LENGTH OF HG-N IS 2.460A AND THE BOND ANGLES AROUND HG ARE FROM 84.20O FOR O(2)–HG(1)–N(2A) TO 159.99O FOR CL(1)-HG(1)-CL(2). IN EACH MOLECULE OF THIS COMPOUND ONE OF THE H- N(AMINE) HYDROGENS OF EACH LIGAND, FORMS A CL-HG... H- N (AMINE) INTERMOLECULAR HYDROGEN BONDING WHICH MAKE POLYMERIC CHAINS IN THE STRUCTURE. THESE CHAINS ARE CONNECTED TO EACH OTHER THROUGH C-H...C, C-H...H-C AND C-H...CL (2) WEAK INTERMOLECULAR ELECTROSTATIC INTERACTIONS TO FORM A THREE DIMENSIONAL NETWORK IN THE CRYSTAL LATTICE.

PHOSPHORIC TRIAMIDE, DFT CALCULATIONS, SOLVENT EFFECT, PCM INTRODUCTION NOWADAYS, RESEARCH ON COORDINATION CHEMISTRY OF PHOSPHORAMIDE LIGANDS HAS ATTRACTED MUCH ATTENTION THAT IS OWING TO THE VALUABLE APPLICATIONS OF THE PHOSPHORAMIDE COMPOUNDS AS ANTI-HIV [1], ANTI-HCV [2], ANTIBACTERIAL [3], ANTITUMOR AND ANTICANCER ACTIVITIES [4] ENZYME INHIBITORS [5] AND CATALYSTS IN CHEMICAL REACTIONS [6].COMPUTATIONAL DETAILS THE STRUCTURE OF A NEW PHOSPHORIC TRIAMIDE WITH FORMUAL 4-CH3-C6H4S (O) 2NHP (O) (NHCH2C4H5) 2WAS OPTIMIZED IN BOTH GAS PHASE AND IN ETHANOL SOLUTION USING GAUSSIAN 98 PROGRAM [7] AT DFT (B3LYP) LEVEL OF THEORY WITH STANDARD 6-31+G** BASIS SET. THE POLARIZED CONTINUUM MODEL (PCM) CALCULATIONS WERE DONE TO MINIMIZE THE STRUCTURE IN SOLUTION STATE.

BACKGROUND: NICOTINAMIDE IS A PART OF THE PYRIDINE NUCLEOTIDES AS NADC AND NADPC THAT PLAYS A CRUCIAL ROLE IN BIOLOGICAL OXIDATIVE CHEMISTRY AND IS ESSENTIAL FOR THE HUMAN BODY [1, 2]. PHOSPHORAMIDES HAVE UNIQUE ANTI-HIV, ANTI-HCV, ANTIBACTERIAL AND ANTICANCER PROPERTIES [3].METHODS: FROM THE REACTION OF PCL5 AND NICOTINAMIDE, OXIDATION AND ADDING HETEROCYCLIC AMINE TO THE INTERMEDIATE AND THEN PURIFICATION WITH SOLVENTS WE SYNTHESIZED SOME NEW PHOSPHORAMIDES CONTAINING NICOTINAMIDE WITH FORMULA: C5H4NC (O) NHP (O) (R)2, R=NC4H8 (1), NC5H10 (2), NC6H12 (3), 4-CH3- NC5H9 (4), NC4H8O (5) AND CHARACTERIZED THEM BY 1H, 13C, 31P, NMR, IR SPECTROSCOPY, ELEMENTAL ANALYSIS AND X-RAY CRYSTALLOGRAPHY.RESULTS: 1HNMR SPECTRA OF COMPOUND 2 DEMONSTRATED LONG-RANGE PHOSPHOROUS-HYDROGEN COUPLING CONSTANT, NJP, H (N=5, 7). THE CRYSTAL STRUCTURE OF 3 WAS DETERMINED BY X-RAY CRYSTALLOGRAPHY (SEE BELOW). IT SHOWS THAT THE P-NAMIDE BONDS ARE LONGER THAN THE P-NAMINE BONDS AND THE C-NAMIDE BOND LENGTHS ARE SHORTER THAN THE C-NAMINE BOND LENGTHS.CONCLUSION: SOME NEW PHOSPHORAMIDES WERE SYNTHESIZED IN WHICH RESONANCE INTERACTION OF THE NAMIDE WITH THE C=O P SYSTEM CAUSES A PARTIAL MULTIPLE BOND CHARACTER IN C-NAMIDE.

MULTICOMPONENT COUPLING REACTION (MCR) IS A POWERFUL SYNTHETIC TOOL FOR THE SYNTHESIS OF BIOLOGICALLY ACTIVE COMPOUNDS. DEVELOPMENT OF SUCH MULTICOMPONENT COUPLING REACTION STRATEGIES IN SOLVENT-FREE MEDIUM HAS BEEN OF CONSIDERABLE INTEREST, AS THEY PROVIDE SIMPLE AND RAPID ACCESS TO A LARGE NUMBER OF ORGANIC MOLECULES THROUGH A SUSTAINABLE PATH. ONE IMPORTANT ASPECT OF GREEN CHEMISTRY IS THE ELIMINATION OF SOLVENTS IN CHEMICAL PROCESSES OR THE REPLACEMENT OF HAZARDOUS SOLVENTS WITH RELATIVELY BENIGN SOLVENTS. A NOVEL FOUR-COMPONENT REACTION APPROACH TO THE EFFICIENT SYNTHESIS OF TRIAMIDE DERIVATIVES USING AMINES, ALDEHYDES AND ALKYL OR ARYL ISOCYANIDES IN THE PRESENCE OF MELDRUM’S ACID AS A CH ACID, INSTEAD OF CARBOXYLIC ACID OF UGI FOUR-COMPONENT REACTION UNDER SOLVENT-FREE CONDITIONS, WAS STUDIED.

PHOSPHORIC ACID IS ONE OF THE MOST WIDELY USED ACIDS.INDUSTRIAL PRODUCTION OF PHOSPHORIC ACID IS ACCOMPLISHED EITHER BY WET METHOD FOR LESS PURIFIED OR DRY METHOD FOR HIGH PURIFIED PHOSPHORIC ACID.IN DRY METHOD, PHOSPHATE ROCK IS REDUCED IN AN ELECTRIC FURNACE TO GIVE PHOSPHOROUS COMPOUND AND THEN BURNING IN EXCESS AIR IT GIVES PHOSPHORIC ANHYDRIDE WHICH IS THEN HYDRATED TO GIVE PHOSPHORIC ACID. IN THE WET METHOD, PHOSPHATE ROCK IS DISSOLVED IN SULFURIC ACID.WET-PHOSPHORIC ACID CONTAINS A WIDE RANGE OF MINERAL IMPURITIES AND DUE TO THESE IMPURITIES THE PHOSPHORIC ACID IS USUALLY GREEN-COLORED.IT IS GENERALLY POSTULATED TO BE DUE TO CERTAIN INCIDENTAL METAL IMPURITIES WHICH EXIST AS CHROMOPHORES.IN ORDER TO OBTAIN A FOOD-GRADE ACID, IT MUST BE PURIFIED.IN THIS PROJECT WE AIMED TO DECOLORIZE AND PURIFY THE WET GREEN-COLORED PHOSPHORIC ACID.SAMPLES WERE TAKEN FROM CORPORATION LOCATED IN IRAN.INITIAL SPECTROPHOTOMETRIC EXPERIMENTS REVEALED THAT THE WET-PHOSPHORIC ACID CONTAINS ORGANIC MATERIALS AND BASED ON THE GREEN COLOR OF THE ACID, THE TOC (TOTAL ORGANIC CARBON) WOULD BE LESS THAN 500 PPM.ELEMENTAL IMPURITIES WERE INVESTIGATED BY ICP WHICH CONSTITUTES THE FOLLOWING: (FE): 80 PPM; (AS): 9 PPM; (CD): 30 PPM; (CR): 32 PPM. ELEMENTAL IMPURITIES ARE NEEDED TO BE REMOVED IN THE CASE THAT THE ACID’S COLOR IS STILL TARNISHED AFTER ORGANIC MATERIALS ELIMINATION. IN ORDER TO REMOVE THE GREEN COLOR FORM THE SOLUTION, A PROCEDURE WAS EMPLOYED. SAMPLE SOLUTIONS WERE HEATED AND AFTER COOLING THE SOLUTION SOME ORGANIC IMPURITIES WERE PRECIPITATED AND THEN FILTERED OFF. TO REMOVE THE REMAINED ORGANIC MATERIALS THE SOLUTION WAS TREATED WITH OXIDIZING AGENTS INCLUDING CHLORINE, H2O2 AT A TEMPERATURE IN THE RANGE OF ABOUT 50 TO ABOUT 150 TO OXIDIZE THE ORGANIC IMPURITIES. VARIOUS PARAMETERS OF THE EXPERIMENT WERE INVESTIGATED AND OPTIMIZED E.G. THE TEMPERATURE, THE OXIDANT CONCENTRATION, THE DURATION OF HEATING AND ETC. DUE TO THE COLOR OF THE OXIDIZED MATERIALS IT IS NEEDED A FURTHER STEP TO DECOLORIZE THE SOLUTION. AN ADSORBENT WAS INTRODUCED TO THE SYSTEM IN ORDER TO ADSORB THE OXIDIZED IMPURITIES. AFTER MIXING WELL, THE SOLUTION WAS PROPOSED TO A SIMPLE DISTILLATION PROCESS TO RESULT A PURE-DISCOLORED PHOSPHORIC ACID. ALTERNATIVELY, IT MAY BE PROPOSED TO A FILTERING PROCESS TO ONLY RESULT A CLEAR PHOSPHORIC ACID.THE METHOD DESCRIBED A SIMPLE PROCESS TO OBTAIN A DISCOLORED/PURIFIED PHOSPHORIC ACID. THE METHOD COMPETES IN PRODUCTION PRICES AND CAPITAL BUDGETS COMPARING TO SOLVENT EXTRACTION METHOD WHICH NEEDS MORE TIME AND VALUABLE SOLVENTS AND ALSO COMPARING TO DRY METHOD WHICH USES A HIGH ELECTRICAL CONSUMPTION FURNACE.