DFT Studies of Caffeic Acid Antioxidant: Molecular Orbitals and Composite Reactivity Maps Correlation with Photophysical Characteristics and Photochemical Stability

<div>Ionization potential map. The local ionization potential map, defined as the sum over orbital electron densities, <svg height="12.7178pt" id="M78" style="vertical-align:-3.42947pt" version="1.1" viewbox="-0.0498162 -9.28833 25.3881 12.7178" width="25.3881pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M516 277C516 378 460 448 376 448C335 448 288 434 240 401C158 345 127 277 107 159C53 -161 38 -221 23 -247L28 -261C43 -260 95 -250 114 -226C122 -216 129 -199 146 -75C152 -29 157 0 164 31C182 9 206 -12 237 -12C267 -12 325 8 376 46C451 102 516 179 516 277ZM432 259C432 134 366 40 259 40C236 40 204 48 171 76L195 203C219 327 253 400 326 400C398 400 432 336 432 259Z" id="g113-239"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="539" vert-adv-y="539"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,7.402,0)"><path d="M244 607C244 633 228 655 200 655C166 655 146 618 146 594C146 564 166 546 191 546C221 546 244 574 244 607ZM222 91L209 114C184 94 148 66 133 66C127 66 124 73 130 96L201 370C213 416 211 448 191 448C162 448 88 407 29 352L42 328C73 354 104 371 114 371C120 371 119 365 115 345L53 92C32 5 45 -12 68 -12C103 -12 186 50 222 91Z" id="g113-106"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="273" vert-adv-y="273"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,10.951,0)"><path d="M300 -147C201 -63 143 98 143 270S200 602 300 686L282 710C136 610 70 450 70 271V270C70 89 136 -72 282 -170L300 -147Z" id="g113-41"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="346" vert-adv-y="346"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,15.449,0)"><path d="M220 349V455C158 436 98 425 38 417V389C85 378 92 374 92 323V104C92 43 83 38 28 32V0H302V32C225 38 220 43 220 104V291C237 330 257 343 276 343C292 343 305 336 322 322C329 316 339 313 353 318C379 328 402 356 402 392C402 426 374 454 335 454C297 454 259 411 222 349H220Z" id="g13-112"></path><glyph.data ascent="1024" descent="-360" horiz-adv-x="404" vert-adv-y="404"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,20.701,0)"><path d="M275 270C275 450 212 609 64 710L45 686C145 604 203 442 203 270S147 -63 45 -147L64 -170C213 -68 275 89 275 270Z" id="g113-42"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="346" vert-adv-y="346"></glyph.data></g></svg> times absolute orbital energies, <i>∈</i><svg height="8.8423pt" id="M79" style="vertical-align:-0.2064009pt" version="1.1" viewbox="-0.0498162 -8.6359 3.66193 8.8423" width="3.66193pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M244 607C244 633 228 655 200 655C166 655 146 618 146 594C146 564 166 546 191 546C221 546 244 574 244 607ZM222 91L209 114C184 94 148 66 133 66C127 66 124 73 130 96L201 370C213 416 211 448 191 448C162 448 88 407 29 352L42 328C73 354 104 371 114 371C120 371 119 365 115 345L53 92C32 5 45 -12 68 -12C103 -12 186 50 222 91Z" id="g113-106"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="273" vert-adv-y="273"></glyph.data></g></svg>, and divided by the total electron density, <svg height="12.7178pt" id="M80" style="vertical-align:-3.42947pt" version="1.1" viewbox="-0.0498162 -9.28833 21.4343 12.7178" width="21.4343pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M516 277C516 378 460 448 376 448C335 448 288 434 240 401C158 345 127 277 107 159C53 -161 38 -221 23 -247L28 -261C43 -260 95 -250 114 -226C122 -216 129 -199 146 -75C152 -29 157 0 164 31C182 9 206 -12 237 -12C267 -12 325 8 376 46C451 102 516 179 516 277ZM432 259C432 134 366 40 259 40C236 40 204 48 171 76L195 203C219 327 253 400 326 400C398 400 432 336 432 259Z" id="g113-239"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="539" vert-adv-y="539"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,7.01,0)"><path d="M300 -147C201 -63 143 98 143 270S200 602 300 686L282 710C136 610 70 450 70 271V270C70 89 136 -72 282 -170L300 -147Z" id="g113-41"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="346" vert-adv-y="346"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,11.508,0)"><path d="M220 349V455C158 436 98 425 38 417V389C85 378 92 374 92 323V104C92 43 83 38 28 32V0H302V32C225 38 220 43 220 104V291C237 330 257 343 276 343C292 343 305 336 322 322C329 316 339 313 353 318C379 328 402 356 402 392C402 426 374 454 335 454C297 454 259 411 222 349H220Z" id="g13-112"></path><glyph.data ascent="1024" descent="-360" horiz-adv-x="404" vert-adv-y="404"></glyph.data></g><g transform="matrix(.013,0,0,-0.013,16.76,0)"><path d="M275 270C275 450 212 609 64 710L45 686C145 604 203 442 203 270S147 -63 45 -147L64 -170C213 -68 275 89 275 270Z" id="g113-42"></path><glyph.data ascent="3473" descent="-2876" horiz-adv-x="346" vert-adv-y="346"></glyph.data></g></svg>. The local ionization potential reflects the relative ease of electron removal (ionization) at any location around CA molecule.</div>

Journal of Chemistry

fig11

Figure 11

Figure 11: DFT Studies of Caffeic Acid Antioxidant: Molecular Orbitals and Composite Reactivity Maps Correlation with Photophysical Characteristics and Photochemical Stability 

Figure 11 | DFT Studies of Caffeic Acid Antioxidant: Molecular Orbitals and Composite Reactivity Maps Correlation with Photophysical Characteristics and Photochemical Stability 