THE LONG LASTING INTEREST IN THE HYDROGEN BONDING PHENOMENON IS DUE TO THE ROLE IT PLAYS IN DETERMINING MOLECULAR STRUCTURE, FUNCTION AND DYNAMICS OF A GREAT NUMBER OF CHEMICAL COMPOUNDS RANGING FROM INORGANIC TO BIOLOGICAL. AMONG VARIOUS HYDROGEN BOND MOTIFS THOSE INVOLVING OXIMES PLAY AN IMPORTANT ROLE IN MOLECULAR DESIGN [1]. FORMALDOXIME IS THE SIMPLEST MEMBER OF THE OXIMES FAMILY, AN IMPORTANT BIOLOGICAL AND CHEMICAL GROUP OF COMPOUNDS. IT IS A STRUCTURAL ISOMER OF FORMAMIDE AND IS BEING CONSIDERED AS A POTENTIAL INTERSTELLAR MOLECULE [2]. THE STRUCTURES OF BOTH MONOMERS (CH2NOH, H2O2) AND THE STRUCTURES OF THE CH2NOH-H2O2 COMPLEXES WITH THE STOICHIOMETRY 1: 1; 1: 2 AND 1: 3 WERE FULLY OPTIMIZED AT THE MP2 AND B3LYP LEVELS OF THEORY WITH THE 6-311++G (2D, 2P) BASIS SET. VIBRATIONAL FREQUENCY CALCULATION WERE CARRIED OUT FOR ALL COMPLEXES AT THE B3LYP/6- 311++G (2D, 2P) LEVEL TO CALCULATE THE ZERO POINT ENERGY (ZPE).THE INTERACTION ENERGIES INDICATED THAT MOST STABLE 1: 1 COMPLEX, IS STABILIZED BY TWO HYDROGEN BONDS O-H…N (CH2NOH ACTS AS A PROTON ACCEPTOR) AND O-H…O (CH2NOH ACTS AS A PROTON DONOR), WHICH FORM A CYCLIC STRUCTURE. IN THE MOST STABLE CH2NOH-H2O2 COMPLEX OF THE 1: 2 STOICHIOMETRY ONE OF TWO H2O2 MOLECULES OF (H2O2) 2 ACTS AS A PROTON DONOR TOWARD THE NITROGEN ATOM AND THE SECOND H2O2 MOLECULE SERVES AS A PROTON ACCEPTOR FOR THE NOH GROUP OF CH2NOH. IN CONTRAST WITH THE SIX-MEMBERED RING IN THE 1: 1 COMPLEX, THE NINEMEMBERED RING IN THE 1: 2 ONE ALLOWS FOR THE MORE EFFECTIVE INTERACTION BETWEEN CH2NOH AND (H2O2) 2. IN THE MOST STABLE COMPLEX OF THE 1: 3 STOICHIOMETRY BETWEEN CH2NOH AND (H2O2) 3 ONE OF THE THREE H2O2 MOLECULES ACT AS A PROTON DONOR TOWARD THE OXYGEN ATOM OF CH2NOH AND THE SECOND H2O2 MOLECULES ACTS LIKE THE MOST STABLE 1: 2 COMPLEX. RESULTS INDICATE THAT THE HYDROGEN BOND INTERACTION IN THE 1: 3 COMPLEX IS STRONGER THAN IN 1: 2 AND 1: 1 COMPLEXES. NATURAL BOND ORBITAL ANALYSIS DATA, THE ELECTRON DENSITY AND LAPLACIAN PROPERTIES HAVE BEEN USED TO EVALUATE THE HYDROGEN BONDING INTERACTIONS.

FORMALDOXIME, IS THE SIMPLEST MEMBER OF THE OXIMES FAMILY, AN IMPORTANT BIOLOGICAL AND CHEMICAL GROUP OF COMPOUNDS. FORMALDOXIME IN THE CONDENSED PHASE IS READILY TRANSFORMED INTO A SOLID POLYMER (CH2NOH) 3. IN THE ABSENCE OF WATER IT FORMS SALTS WITH ACIDS OF THE TYPE (CH2NOH) 3HCL THAT AFTER HEATING RELEASE MONOMERIC FORMALDOXIME. THE R1R2C=NOH GROUP, CHARACTERISTIC FOR OXIMES, HAS THREE DISTINCT HYDROGEN BONDING SITES AND, SO, OXIMES CAN FORM A VARIETY OF HYDROGEN BONDS. TWO OF THE THREE SITES, THE NITROGEN AND OXYGEN ATOMS, ARE THE HYDROGEN BOND ACCEPTOR SITES AND THE (N) OH GROUP IS A PROTON DONOR. ALTHOUGH THE INTERMOLECULAR HYDROGEN BOND MOTIFS INVOLVING OXIMES PLAY AN IMPORTANT ROLE IN MOLECULAR DESIGN THE HYDROGEN BONDING ABILITIES OF OXIMES WERE MUCH LESS STUDIED. IN THE PRESENT WORK, WE INVESTIGATED THE HYDROGEN BONDING INTERACTION BETWEEN H2O2 AND FORMALDOXIME. HYDROGEN PEROXIDE IS AN UBIQUITOUS MOLECULE AND WELL-KNOWN FOR ITS BACTERICIDAL AND OXIDIZING PROPERTIES. IT PLAYS SIGNIFICANT ROLES IN BIOLOGICAL AND CHEMICAL PROCESSES.

NITRILE OXIDE 1, AFFORDED IN SITU FROM THE REACTION OF DIBROMO FORMALDOXIME AND KHCO 3, REACTS WITH THE OLEFIN COMPOUNDS TO GIVE BROMOISOXAZOLINES IN SATISFACTORY YIELDS [1-4]. REACTION OF INDENO [1, 2- B ] QUINOXALIN-11-ONE2 WITH 1-PHENYL-2- (TRIPHENYLPHOSPHANYLIDENE) -ETHANONE3IN ETHANOL RESULTEDIN 2-INDENO [1, 2- B ] QUINOXALINE-11-YLIDENE-1-PHENYL-ETHANONE (CORRESPONDING CHALCONE) 4 AT ROOM TEMPERATURE.1, 3-DIPOLAR CYCLOADDITION….