Arijit Das

New Innovative Methods for Prediction of Hybridization State in a Very Short Time

Prediction of hybridization state is a vitally important to students of chemistry in undergraduate, graduate and also in Post-graduate level. The method which is generally used for determination of hybridization state to find out the geometry is time consuming. To keep the matter in mind a new innovative method has to be introduced for calculation of hybridization state in a very simple way, which is also be a time savings one. Experiment in vitro on 100 number of students showed that for determination of Hybridization state, using old method,strike rate is 1Q/5min and by using these new innovative methods strike rate is 1Q/5secs. On the basis of this experiment I can strongly recommend that these new methods will be the very rapid one for the determination of hybridization state. INTRODUCTION A clear understanding and prediction of hybridization states are vitally important to students of chemistry in undergraduate, graduate and also in Postgraduate level to solve different kind of problems related hybridization state1,2,3. The method which is generally used for determination of hybridization state is time consuming4. This new innovative method for prediction of hybridization states would go a long way to help to the students of chemistry who would choose the subject as their career. We Know, Hybridization is nothing but the mixing of orbital’s in different ratio to form some newly synthesized orbital’s called hybrid orbitals. The mixing pattern is as follows: Mixing Hybrid orbital Power of the Hybridization s + p (1:1) sp hybrid orbital 01 s + p (1:2) sp2 hybrid orbital 02 s + p (1:3) sp3 hybrid orbital 03 Formula for determination of hybridization state like sp, sp2, sp3 followed the following method: Power of the Hybridization state of the centre atom = (Total no of σ bonds around each centre atom -1) All single (-) bonds are σ bond, in double bond (=) there is one σ and 1π, in triple bond there is one σ and 2π. In addition to these each lone pair (i.e.no of electrons in the outermost orbit which should not take part in bond formation) and Co-ordinate bond can be treated as one σ bond. Eg:1. In NH3, centre atom N is surrounded by three N-H single bond i.e. three sigma (σ ) bonds and one LP i.e. one additional σ bond. So, altogether in NH3 there is four σ bonds (3BP + 1LP) around centre atom N, So, in this case Power of the Hybridization state of N = 4-1 =3 i.e. hybridization state=sp3. 2. In H2O, centre atom O is surrounded by two O-H single bond i.e. two sigma (σ) bonds and two LPs i.e. two additional σ bonds. So, altogether in H2O there is four σ bonds (2BPs + 2LPs) around centre atom O, So, in this case Power of the Hybridization state of O = 4-1 =3 i.e. hybridization state of O in H2O = sp 3. 3. In H3BO3 (AIEEE-04) -

New Innovative Methods for Determination of Spin Multiplicity, Spin State and Magnetic Properties of Diatomic Hetero Nuclear Molecules or Ions in a Very Short Interval of Time

Evaluation of spin-multiplicity value is a vitally important tool for prediction of spin state of atoms, molecules, ions or co-ordination complexes to students of chemistry in undergraduate, graduate and also in post-graduate level students for solving different kinds of problems. This new innovative method has to be introduced for the calculation of spin-multiplicity value in the easiest way by ignoring the calculation of total spin quantum number (S = Σs). Another method has also to be introduced for resolving magnetic nature of diatomic heteronuclei molecules or ions in a very simple way. INTRODUCTION The method which is generally used1,2,3,4,5 for the prediction of spin multiplicity value [(2S+1), where S = Σs = total spin quantum no] is time consuming. To keep the matter in mind a new innovative method has to be introduced for calculation of spin-multiplicity value in the easiest way by ignoring the calculation of total spin quantum number (S = Σs). Another method has also to be introduced for resolving magnetic behavior of diatomic hetero nuclear molecules or ions like CO, NO, NO+, NO-, CN, CNetc. in a very simple way. Another three innovative methods earlier introduced on the easy prediction of ‘Hybridization’, ‘Bond-Order’ and ‘IUPAC nomenclature of spiro and bicyclo compounds6,7,8 for the benefit of students. These new innovative methods would go a long way to help to the students of chemistry who would choose the subject as their career. Experiment in vitro on 100 number of students show that for determination of spin multiplicity value using old (2S + 1) rule, strike rate is 1Q/3min and by using these new innovative methods strike rate is 1Q/5secs. On the basis of this experiment I can strongly recommend that these new methods will be the very rapid one for the determination of spin-multiplicity value and its corresponding spin-state (Table-1) by ignoring the calculation of total spin quantum number (S = Σs) in (2S + 1) rule. New innovative methods for determination of spin multiplicity: First of all we should classify the species (atoms, molecules, ions or complexes) for which spin multiplicity should be evaluated into three types based on the nature of alignment of unpaired electrons present in them. a) Species having unpaired electrons alignment upward arrow (↑): In this case, spin multiplicity = (n+1); where n = number of unpaired electrons. ↑ Spin multiplicity = (n +1) = (1+1) = 2 (spin state = doublet) ↑ ↑ Spin multiplicity = (n +1) = (2+1) = 3 (spin state = triplet) ↑ ↑ ↑ Spin multiplicity = (n +1) = (3 + 1) = 4 (spin state = quartet) ↑↓ ↑ ↑ Spin multiplicity = (n +1) = (2 + 1) = 3 (in this case ignore paired electrons) (spin state = triplet) ↑↓ ↑↓ ↑ Spin multiplicity = (n +1) = (1 + 1) = 2 (spin state = doublet) ↑↓ ↑↓ ↑↓ Spin multiplicity = (n +1) = (0 + 1) = 1 (spin state = singlet) b) Species having unpaired electrons alignment downward arrow (↓): In this case spin multiplicity = (-n+1); where n = number of unpaired electrons. Here (-ve) sign indicate downward arrow. ↓ Spin multiplicity = (-n +1) = (-1 + 1) = 0 (where n = no of unpaired e-s) ↓ ↓ Spin multiplicity = (-n +1) = (-2 + 1) = -1 ↓ ↓ ↓ Spin multiplicity = (-n +1) = (-3 + 1) = -2 ↑↓ ↓ ↓ Spin multiplicity = (-n + 1) = (-2 + 1) = -1(in this case ignore paired electrons) ↑↓ ↑↓ ↓ Spin multiplicity = (-n + 1) = (-1 + 1) = 0 c) Species having unpaired electrons alignment both upward and downward arrow In this case spin multiplicity = [(+n) + (-n) + 1]; where n = number of unpaired electrons in each mode. Here, (+ve) sign indicate upward mode of arrow and (–ve) sign indicate downward mode of arrow. ↑ ↓

Six-coordinate cadmium(II) complex containing a bridging dithiolate ligand: synthesis, crystal structure and antifungal activity study

Abstract A mixed-ligand polymeric metal complex of Cd(II) has been prepared by reactions of Cd(NO3)2·4H2O with 1,3-diaminopropane (tn) and potassium salt of 1,1-dicyanoethylene-2,2-dithiolate and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis reveals that the Cd(II) complex crystallizes in monoclinic space group P21/n with distorted octahedral coordination geometry. The Cd(II) complex was screened in vitro against fungal pathogens such as Synchytrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. The biological testing data of the primary ligand K2i-MNT·H2O and [Cd(tn)(i-MNT)]n indicate that the complex exhibits fungistatic antifungal activity, whereas K2i-MNT·H2O has no activity. The fungicidal properties of [Cd(tn)(i-MNT)]n showed that the cadmium complex was more bioactive than the parent ligand.

Cd(II) complexation with 1,1-dithiolate and nitrogen donors: synthesis, luminescence, crystal structure, and antifungal activity study

A new luminescent complex of Cd(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C : C(CN)2}2−] with 1,3-diaminopropane (tn) and 4-methyl pyridine (γ-picoline) as secondary ligands has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis reveals that cadmium(II) is five coordinate in a 1-D polymer. Biological screening effects in vitro of the synthesized complex has been tested against five fungi Synchytrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. A comparative study of inhibition zone values of K2i-MNT·H2O and {[Cd(tn)(iMNT)(4-MePy)]·4H2O}n (1) indicates that the complex exhibits antifungal activity, whereas K2i-MNT·H2O became silent on S. endobioticum, P. oryzae, H. oryzae, C. albicans (ATCC10231), and T. mentagrophytes. Graphical abstract A new luminescent complex of Cd(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C:C(CN)2}2−] has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis reveals that the cadmium(II) complex is five coordinate in a 1-D polymer. Biological screening in vitro of the complex has been tested against five fungi Synchytrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. The antifungal activity of the complex of Cd(II) is significant compared to K2iMNT on S. endobioticum, P. oryzae, H. oryzae, and T. mentagrophytes and proved to be crucial for the growth-inhibitor effect.

A Rapid and Innovative Method for the Easy Prediction of Magnetic Behavior of Homo and Hetero Nuclear Mono and Diatomic Molecules Or Ions without Mot

Prediction of magnetic state is of vital important tool to students of applied chemistry for solving different kinds of problems related to magnetic behavior and also magnetic moment. In this manuscript I try to present an innovative method for the identification of magnetic behavior of homo and hetero nuclear mono and diatomic molecules or ions having total electrons (01-20) excluding MOT in a very simple and time savings manner. Introduction The conventional method of determination of bond order and magnetic behavior using M.O.T.1,2,3,4,5 is time consuming. Keeping this in mind, earlier a new innovative method10 was introduced for the determination of bond order of mono and diatomic molecules or ions having total electrons (0120) from which we can easily predict the magnetic behavior of different kinds of homo and hetero nuclear mono and diatomic molecules or ions. The present method is the periodical part of the earlier method10, so that student can forecast bond-order including magnetic behavior of mono and diatomic molecules or ions having total electrons (01-20) without M.O.T.. Previously eight innovative methods including twelve new formulae have been introduced on ‘Hybridization’, ‘IUPAC nomenclature of spiro and bicyclo compounds’, ‘Bond Order of oxide based acid radicals’, ‘Bond order of mono and diatomic molecules or ions having total number of (120)e-s’ and ‘spin multiplicity value calculation and prediction of magnetic properties of diatomic hetero nuclear molecules and ions6,7,8,9,10 for the benefit of students. New important findings in case of Magnetic behavior of homo and hetero nuclear mono and diatomic molecules or ions: Before introducing into innovative method for the prediction of magnetic behavior, first of all we shepherd the species (molecules and ions) with respect to their total number of electrons and bond order (Table-1). Table -1 (Magnetic properties of homo and hetero nuclear mono and diatomic molecules or ions) Molecules or ions Total Number of e-s B.O. Magnetism Remarks on BondOrder H2 + 1 0.5 Para magnetic Fractional H2, He2 2+ 2 1 Diamagnetic +ve integer H2 ,He2 + 3 0.5 Para magnetic Fractional He2, 4 0 Diamagnetic +ve integer Li2 ,He2 5 0.5 Para magnetic Fractional Li2, He2 2-, Be2 2+ 6 1 Diamagnetic +ve integer Be2 ,Li2 7 0.5 Para magnetic Fractional Be2,Li2 28 0 Diamagnetic +ve integer Be2 ,B2 + 9 0.5 Para magnetic Fractional B2, Be2 2-, HF 10 1 Para magnetic Exception B2 ,C2 + 11 1.5 Para magnetic Fractional C2,B2 ,N2 2+, CN+ 12 2 Diamagnetic +ve integer C2 ,N2 + 13 2.5 Para magnetic Fractional N2,CO,NO ,C2 2,CN,O2 2+ 14 3 Diamagnetic +ve integer N2 ,NO,O2 + 15 2.5 Para magnetic Fractional NO,O2 16 2 Para magnetic Exception O2 17 1.5 Para magnetic Fractional F2,O2 2-,HCl 18 1 Diamagnetic +ve integer F2 19 0.5 Para magnetic Fractional Ne2 20 0 Diamagnetic +ve integer In most of the cases generally it is observed that the species having fractional bond-order will be paramagnetic in nature and the species having positive integer bond-order (i.e. bond order = 0,1,2,3 etc) will be diamagnetic in nature. But there is some exception focused in two cases during prediction of magnetic behavior of species having total number of electrons 10 and 16 respectively. In both the cases although they have positive integer bond-order values, 1 and 2, but they are paramagnetic in nature instead of diamagnetic. Explanation on Exception behavior: Species having total number of electrons 10 and 16 will be paramagnetic in nature although they have a positive integer bond order value. In this case, first, we have to predict their magnetic behavior from their magnetic moment values by calculating the number of unpaired electrons by the following two formulae based on bond-order. New two formulae for resolving the number of unpaired electrons (n) based on bond-order in case of paramagnetic substances having total number of electrons 10 and 16. When total number of electrons is 10 [The number of unpaired electrons (n) = 2 x bond order] Eg: B2, HF:[10 electrons, B.O. = 1.0; n = 2 x bond order = 2 x 1.0 = 2.0, Magnetic moment μs = √n(n+2) B.M. = √2(2+2)B.M. = √8 B.M. = 2.83B.M.]

Synthesis and characterization of mixed ligand complexes of cobalt(II) with some nitrogen and sulfur donors

Mixed ligand complexes of Co(II) with nitrogen and sulfur donors, Co(OPD)(S–S) · 2H2O and Co(OPD)(S–S)L2 [OPD = o-phenylenediamine; S–S = 1,1-dicyanoethylene-2,2-dithiolate (i-MNT2−) or 1-cyano-1-carboethoxyethylene-2,2-dithiolate (CED2−); L = pyridine (py), α-picoline (α-pic), β-picoline (β-pic), or γ-picoline (γ-pic)], have been isolated and characterized by analytical data, molar conductance, magnetic susceptibility, electronic, and infrared spectral studies. The molar conductance data reveal non-electrolytes in DMF. Magnetic moment values suggest low-spin and high-spin complexes. The electronic spectral studies suggest distorted octahedral stereochemistry around Co(II) in these complexes. Infrared spectral studies suggest bidentate chelating behavior of i-MNT2−, CED2−, or OPD while other ligands are unidentate in their complexes.

Synthesis, crystal structure, and antifungal activity of a newly synthesized polymeric mixed ligand complex of Zn(II) with 1,1-dithiolate and nitrogen donors

A new mixed ligand complex of Zn(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C:C(CN)2}2−] and 1,3-diaminopropane as ligands has been synthesized and characterized on the basis of spectroscopy and single-crystal X-ray diffraction analysis. Spectroscopic studies and single-crystal X-ray diffraction analysis reveal that the zinc(II) complex is tetrahedral and adopts a 1,3-diaminopropane-assisted linear polymeric assembly. The molar conductance data of the complex in DMF solution show non-electrolytic nature. Biological screening effects of the complex in vitro have been tested against five fungi Synchitrium endobioticum, Pyricularia oryzae, Helminthosporium oryzae, Candida albicans (ATCC10231), and Trichophyton mentagrophytes by the disk diffusion method. A comparative study of inhibition zone values of the primary ligand K2i-MNT·H2O and its synthesized complex indicates that the complex exhibits a fungistatic antifungal activity whereas K2i-MNT·H2O does not affect P. oryzae. Graphical Abstract Complex of Zn(II) with 1,1-dicyanoethylene-2,2-dithiolate [i-MNT2− = {S2C:C(CN)2}2−] and 1,3-diaminopropane.

New Methods for Prediction of Bond Order of Mono and Diatomic Homo and Hetero Nuclear Molecules or Ions Having (1-20) E¯S and Oxide Based Acid Radicals Without Mot – A Rapid Innovative Approach

Prediction of bond order is of vital important to students of chemistry for solving different kinds of problems related to bond length, bond strength, bond dissociation energy, thermal stability and reactivity. Keeping this in mind, a new innovative method is presented for calculation of bond order of molecules and ions having total electrons (01-20) in a very simple and time saving manner. This method is applicable for mono atomic and diatomic molecules and ions such as CO, NO+, O2 2+ etc. and is not applicable for polyatomic molecules such as BF3, CH4, CO2 etc. Introduction The conventional method of determination of bond order using M.O.T.1,2,3,4,5 is time consuming. Keeping this in mind, earlier a new innovative method6 was introduced for the determination of bond order of mono and diatomic molecules or ions having total electrons (08-20). The present method with its graphical representation ( Fig-1; b.o. vs total no of e-s) is the periodical part of the earlier method6 (08-20) e-s, so that student can forecast bond-order of mono and diatomic molecules or ions having total electrons (01-20).This method is applicable for mono atomic and diatomic homo and hetero nuclear molecules and ions such as CO, NO+, O2 2+ , H2, H2 +, H2 -, He2, He2 +, He2 ,Li2, Li2 +, Li2 etc. and not applicable for polyatomic molecules such as BF3, CH4, CO2 etc. The Graph Fig-1: Bond-Order vs Total no of electrons. The graphical representation presented in Fig. 1 shows that bond-order gradually increases to 01 in the range (0-02) electrons then it falls to zero in the range (02-04) electrons then it further rises to 01 for (04-06) electrons and once again falls to zero for (06-08) electrons then again rises to 3 in the range (08-14) electrons and then finally falls to zero for (1420) electrons. For total no of electrons 2, 6 and 14, we use multiple formulae, because they fall in the overlapping region in which they intersect with each other. It is generally observed that in most of the cases for homo nuclear diatomic molecules or ions bond order will be fractional and it will also be paramagnetic in nature. First of all we classify the molecules or ions into four (04) types based on the total no of electrons. Molecules and ions having total no of electrons within the range (0-2). In such case Bond order = n/2 ; [Where n = Total no of electrons] Eg: H2 (Total e -s = 02), Therefore B.O. = n/2 = 02/2 = 1 H2 + (Total e-s = 02-1 = 1), Therefore B.O. = n/2 = 01/2 = 0.5

Time Economic Innovative Methodology on the Prediction of Hybridization State of Heterocyclic Compounds

Context based learning approaches have been presented in this article as a way to enhance students interest in, as well as time economic learning outcomes from chemical education. In this article state of s-p hybridization of hetero atoms in heterocyclic compounds is empirically calculate from the number of bonds and delocalized lone pair of electrons associated with it. The article explores the results and gives implications for context-based teaching, learning and assessment.