MRSFall 2006 Meeting Nov.27-Dec.1, 2006 Boston USA This “.ppt” file made in System: IBM PC; MS Windows 98 SE; with MS office XP. The animations are MS Powerpoint XP schemes in the system as above MRSFall 2006 Meeting Nov.27-Dec.1, 2006 Boston USA By ARAVAMUDHAN, Sankarampadi Department of Chemistry North Eastern Hill University SHILLONG 793022 INDIA Session MM17.2: December 1, 2006 11:00AM Title of the Talk: Line Shapes in Magnetic Resonance and the Average Static Magnetic Field in the Medium: The Role of Discreteness and Continuum within the Material PowerPoint Presentation File: Automatic time settings as well as manual clicks are used for advancing display. Slide Transition “On Click”. “Click” and look for changes in display: there may be animations with automatic time settings: wait for 5 secs if no changes occur: Then Click. 2/24/2019 12:50:11 AM MRSFall 2006: Dec.1,2006: MM17.2: 11:00AM

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s The task would be to calculate the induced field inside the cavity σcavity Organic Molecular single crystal : a specimen of arbitrary shape I.V.E Sphere Induced field calculation by discrete summation σinter Continuum σIVE = σinter + σM Discrete I.V.E. Cavity Added σinter Shifts the line position σcavity = σBulk +σM O Inner Volume Element I.V.E H O σintra / σM O O 4 point star indicates the molecule at a central location. Structure of a typical molecule on the right σIVE(S) σM O H In-homogeneity can cause line shape alterations: O not simply shifts only Proton Site with σintra single sharp line 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

Intra molecular Shielding σ=‘σM’ Line (position) shifts & Line shape changes NMR Line for only Intra molecular Shielding σ=‘σM’ Added intermolecular : σInter Contributions causes a shift downfield or up field σ = ‘σM’+‘σInter’ ’+‘σB (homogeneous)’ Homogeneous no line shape alterations Slightly inhomogeneous Nearly spherical & shifted & shifted Highly inhomogeneous Cylindrical Inhomogeneous Magnetization can cause line shape alterationsσ = ‘σM’+‘σInter’ ’+‘σB (in-homogeneous)’ 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

MRSFall 2006/This slide 01m:15s for prev. 7 slides=09m:43s (1-3.cos2θ) term causes +ve & -ve contributing zones See drawing below Lattice summation Shell by Shell Induced field varies as R-3 Number of molecules in successive shells increase as R2 Magnetic Field Product of above two vary as R-1 Each moment contributes to induced field The above distance dependences can be depicted graphically Dashed lines: convergence limit 2 A˚ equal spacing Benzene Molecule & Its magnetic moment When the R becomes large, the R-1 term contribution becomes smaller and smaller to become insignificant -ve zone {χM . (1-3.COS2θ)}/(RM)3 +ve Magnetic field direction 2/24/2019 12:50:11 AM MRSFall 2006/This slide 01m:15s for prev. 7 slides=09m:43s

MRSFall 2006/This slide 01m:40s for prev.6 slides=08m:03s First and Foremost it is to be pointed out that trying to sum the induced field contributions in the discrete region by taking the molecule by molecule contributions from the neighborhood, results in a convergence of the summed value to a total sum, which can be termed as Intermolecular contributions. This convergence is depicted below in the actual single crystalline case of an Organic molecular single crystalline system. The summed up contributions from within Lorentz sphere as a function of the radius of the sphere. The sum reaches a Limiting Value at around 50Aº. These are values reported in a M.Sc., Project (1990) submitted to N.E.H.University. T.C. stands for (shielding) Tensor Component .Convergence occurred in this particular case at 50 Aº radius. 2/24/2019 12:50:11 AM MRSFall 2006/This slide 01m:40s for prev.6 slides=08m:03s

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s Description of a Procedure for Evaluating the Induced Field Contributions from the Bulk of the Medium The Case of a Cylindrically shaped specimen would be illustrated Radial Vector with polar coordinates: r, θ, φ. (Details to find in 4th Alpine Conference on SSNMR presentation Sheets 6-8) http://nehuacin.tripod.com/id1.html 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s Study of PORUS Materials could be complimentary since the voids produce FIELD Gradients. This Field Gradients are attributed (1) to Δχ values among the other specimen characteristic parameters. The field variations due to such Susceptibility Anisotropy are typically the induced field distributions due to in-homogeneity of the specimen medium. The inhomogeneous medium and the summation procedure conveniently applicable are discussed at http://www.geocities.com/inboxnehu_sa/nmrs2005_icmrbs.html Thus the methods of calculating the induced fields by the alternative summation procedure could further substantiate the trends and applicability of the experimental procedures for the measurement of induced field distribution. Internal Magnetic Field Gradients: Experimental Study, Page 153 Abstract EMR-17, EUROMAR2008 Reference therein: Song,Y.-Q. Using Internal magnetic Fields…..Pore Size Distributions….Porus Media, Concepts In Magnetic Resonance, 2003, V.18A, No2,P,97-110 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s Correlating ‘r’ and ‘r -3’ Calculation of the Induced Field Distribution in the region outside the magnetized spherical specimen 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s A cylinder shaped specimen (Blue line in the plot below) The points on the Blue line would be specified and at these Calculated field values an NMR line would be placed after adding the sum total of intra and intermolecular contributions to induced fields. Calculations at 9 points along the axis Zero ind. Field Points Not to be discussed in this presentation Distance along the axis 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

Only inter molecular value 5 Only inter molecular value 5.80E-07 was added and the line shape was plotted with those values : NEXT GRAPHICAL PLOT A Graph of the data in table Cylinder By Calculation Trend line interpolation 7 -2.87E-07 -2.9E-07 6 -1.9E-07 5 -1.87E-07 -1E-07 4 3.25E-08 -2.8E-08 3 2.8E-08 2 6.45E-08 6.8E-08 1 9.2E-08 9.35E-08 1E-07 -1 -2 -3 -4 -5 -6 -7 Overlapping last three lines Lines at interpolated values Only inter molecular value 5.80E-07 can be set = 0 No intra molecular Value; inter- molecular value (in I.V.E) set=0 in subsequent plots; only cavity field is used to generate line shapes 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s Same graph as displayed in previous slide Gradual increase of component lines broadens the lines and can cause the change in the appearance of overall shape. Illustration with 4 different width values 10 times that of red Width 2.5 times that of green Width twice that of blue Width twice that of red Same width as above 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s Line at σIVE 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s

QUESTIONS, REMARKS & COMMENTS Picture: A VIEW at NEHU Campus END OF PRESENTATION QUESTIONS, REMARKS & COMMENTS Picture: A VIEW at NEHU Campus 2/24/2019 12:50:11 AM MRSFall 2006/This slide 02m:01s for prev. 12 slides=16m:34s