Chemistry in the 21st century: Looking into the future

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    ISSN 1019-3316, Herald of the Russian Academy of Sciences, 2009, Vol. 79, No. 2, pp. 122129. Pleiades Publishing, Ltd., 2009.Original Russian Text V.A. Tartakovskii, S.M. Aldoshin, 2009, published in Vestnik Rossiiskoi Akademii Nauk, 2009, Vol. 79, No. 3, pp. 229237.

    Our paper is based on predictive analysis of chemis-try development in the 21st century and was preparedjointly with Academicians A.L. Buchachenko,V.I. Minkin, A.I. Konovalov, I.I. Moiseev, andYu.D. Tretyakov and with the participation of Acade-micians A.R. Khokhlov, A.G. Merzhanov, R.Z. Sag-deev, and G.A. Abakumov and RAS CorrespondingMembers G.B. Manelis, S.D. Varfolomeev, andV.I. Ovcharenko. In fact, our paper is a collective workof the RAS Branch of Chemistry and Materials Sci-ences. We will discuss prospects for the development ofchemistry in this century.

    All substances obtained by chemists are the result ofunorganized chemical reactions, in which atoms andmolecules meet at random in time and space. At thesame time, chemistry in nature builds all its objectsrelying on the high organization of the molecular andsupramolecular structure. The awareness of this factand the orientation of chemistry toward molecular andsupramolecular organization is a strategic trend in thedevelopment of chemistry in the 21st century. There-fore, let us begin with

    supramolecular chemistry.

    Thisscience appeared in Russia about 30 years ago andstarted to develop in Moscow, Novosibirsk, Kazan, andother cities. At present, it has achieved brilliant suc-cesses mainly thanks to the findings of the scientificschools of Academicians Konovalov, M.V. Alfimov,and A.Yu. Tsivadze and some other research centers.

    It is obvious today that supramolecular systemshave a special niche or level in the hierarchy of matter.The atomic level is followed by the molecular one withthe covalent form of binding between atoms. Thencomes the supramolecular level with noncovalent(intermolecular) binding. Supramolecular systemsemploy organizational and functioning principles ofmatter, such as molecular recognition, selective bind-ing, receptorsubstrate interaction, transmembranetransport, and supramolecular catalysis. Molecular rec-ognition (which is chemical informatics) serves as thebasis for the self-organization and programmable self-assembly of supramolecular systems, which were uti-lized to the maximum during the formation of biologi-cal objects. The key structures of biological systems,

    for example, the double helices of nucleic acids, cellmembranes, and enzymes, are supramolecular systems.

    Proceeding from the above principles of organiza-tion and function of supramolecular systems and theirvery close structural and functional relation to biologi-cal objects, we predict two crucial and basic ways ofdevelopment of supramolecular chemistry in the21st century. First is the development of methods ofsupramolecular chemistry as an instrument of con-structing nanoparticles and nanomaterials with presetproperties and the use of the programmable self-assem-bly of supramolecular systems. Second is the creationof artificial systems (including natural analogs) capableof interaction with biological objects at the supramo-lecular level (Fig. 1).

    Chemistry has reached the topmost horizon: theability to detect, spatially fix, transfer, and recognize asingle molecule and measure almost all its materialproperties. This topmost horizon creates the elementbase and develops technologies to manipulate singlemolecules for nanooptics, nanomechanics, and nano-electronics. This is a prologue to a new technologicalcivilization,

    molecular electronics

    , which operates onmillivolts and nanoamperes.

    Developed countries already have dozens of labora-tories duly equipped, and billions of dollars are allo-cated to finance them. The scientific world is in a race,being clearly aware that the position of any country inthe hierarchy of developed countries depends on break-throughs in this sphere.

    Molecular electronics and spintronics are the mostrapidly developing spheres of nanotechnology, whoseorigin and development sociologists view as the fifthindustrial revolution. Let us briefly overview the devel-opment of this field of chemistry. Assumptions thatmolecules can conduct electric current were made backin the early 1950s by R.S. Mulliken and A. Szent-Gyr-gyi, but usually the origin of molecular electronics isassociated with the 1974 publication of A. Aviram andM. Ratner. They proposed the idea of a molecular rec-tifier (diode): a molecule containing powerful

    -donorand

    -acceptor groups, divided by a

    -spacer, andplaced between the electrodes. Such molecules modelthe

    pn

    junction in semiconductors (Fig. 2).

    DOI:

    10.1134/S1019331609020075

    Chemistry in the 21st Century: Looking into the Future

    Paper by Academicians V. A. Tartakovskii and S. M. Aldoshin

    Scientific Session of the General Meetingof the Russian Academy of Sciences

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    CHEMISTRY IN THE 21st CENTURY: LOOKING INTO THE FUTURE 123

    The next stage is the synthesis and study of various

    molecular switchers

    and

    molecular wires.

    The lattercan have quite unusual structures. An example is poly-diacetylene encapsulated in polysaccharide shizofillanwith a resulting spiral structure.

    The creation of a diversified spectrum of switchersand nanowires gave us the opportunity to form logicaldevices on their basis. We assume that a new moleculartechnology will appear by 20202025. In addition,

    quantum computers will appear in another 1020 years.The architecture of such a molecular computer isassumed to be similar to a silicon computer. However,logical gates and smart molecules carry out logical con-nections between individual elements of this computer.

    The elemental base of molecular computers is

    bistable molecular

    and

    supramolecular structures

    These are structures that exist in two (or several) ther-modynamically stable states, met by local minima on

    Nanoreactors

    Photonic crystals

    Phonon glass

    Devices for quantumcomputers Nano- and microcontainers(target delivery)

    Nanobots

    Molecular machines

    Hydrogen and methane accumulators

    Phononic scatteringon quest oscillations

    Conductingframe

    ~ 1415

    Supramolecularsystems

    Fig. 1.

    Expected practical results of supramolecular chemistry.

    Fig. 2.

    Main stages of the development of molecular electronics.

    1970 1980 1990 2000 2010 2020

    1974A. Aviram,M. RatherMolecularpn Junction

    D

    (

    n

    )

    A(p)

    Molecularswitches2-D and 3-D molecular memorynanowires

    Molecularlogicalgates

    Creatinga molecularcomputer

    on nanowires

    off

    D

    -

    -

    Molecular junction

    Polyacetylene in the polysaccharideshizofillan shell

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    polyethylene foam. Switching between these states isdone by various external impacts. In terms of informat-ics, such structures may be associated with the notionof logical zero (0) and one (1), and their regroupings,with information transfers.

    Supramolecular formations capable of light-trig-gered reversible regroupings are qualified as photo-chromic systems. An example is chromenic, fulgidic,spiropyranic, and spirooxazine systems, which werestudied in our country by Academicians Minkin,Aldoshin, and Alfimov, Doctor of Chemical SciencesM.M. Krayushkin, and other chemists. They operate atroom temperature and have response times to externalimpacts, that is, reactions of femtoseconds, and equilib-rium times of picoseconds. 3-D optical memorydevices based on these systems ensure a colossal writ-ing density. Even a 532-nm laser writes informationwith a density of 10

    13

    bit/cm

    3

    , and a UV laser increasesthis value by an order of magnitude.

    The first

    3-D optical memory

    devices, multilayerfluorescent disks, were based on indolylfulgides, pho-tochromic compounds first obtained at Rostov StateUniversitys Research Institute of Physical and OrganicChemistry and at the Mendeleev Technological Univer-sity and studied at the Photochemistry Center and theRAS Institute of Problems of Chemical Physics. Thesecompounds, especially 2-indolylfilgides, are character-ized by an exceptionally high thermal stability. Thecyclic form has a fluorescence by which information isread. The bit area on such disks is about hundredths ofa square micron, or 10 000 nm

    2

    . This is the area of thou-sands of molecules. Professor A. Irie from Japan hasshown with a similar system that the bit area can bereduced to the size of one molecule.

    An especially promising trend in the creation of

    materials with ultrahigh magnetic memory

    (one mole-cule, one bit) is the development of monomolecularmagnets. Although magnetism is a collective property,metalloorganic clusters, characterized by (i) the mainhigh-spin state, (ii) a large magnetic anisotropy relativeto the most energy-favorable direction of spontaneousmagnetization, and (iii) the absence of, or weak, mag-netic interactions between molecules, display the prop-erties of a permanent magnet.

    An important indicator is blocking temperature(below which relaxation becomes very slow). At 1.5 K,cluster Mn

    12

    retains magnetization for 40 years, and, at2 K, for two months and only 40% of magnetization.

    The smallest monomolecular magnet produced thusfar contains only five metallic centers. The largest oneis a nanoparticle of 42 nm in diameter.

    Blocking temperatures for all currently knownmolecular magnets do not exceed 3 K, which is prede-termined by very small values of energy barriers.

    The problem of obtaining high-spin clusters hasbeen solved successfully. For example, a cluster hasbeen obtained to have 83 parallel electronic spins in the

    main electronic state. However, the main problem andthe main search direction are compounds with a highanisotropy relative to the axis of easy magnetization.

    The above data indicate considerable progress in thesphere of fast optical molecular switches and high-capacity memory devices. In fact, the maximum possi-ble indicators have been reached at the molecular level:the speed of an elementary response and a writing den-sity of one bitone molecule.

    A way to control these molecular systems to date isthe transmission of electric signals. Therefore, 21st-century chemistry is facing the task of creating

    molec-ular rectifiers

    and

    molecular wires.

    The search for molecules that can conduct electriccurrent is very active indeed. According to theoreticalestimates, such systems can be obtained by designingflat and linear aromatic structures in which the energygap between the lowest free and the highest filled orbit-als is the smallest. Nevertheless, the estimates showthat it will still be higher than 1.5 eV.

    Another search area is oligomeric metallocomplexstructures. The most promising here is porphyrinicpolymers (Academician Tsivadze and RAS Corre-sponding Member O.N. Koifman).

    It is assumed that the best candidates for molecularconductors are linear conjugated oligomeric structureswith a section of about 0.3 nm and a length from 1 to100 nm. Such oligomers were obtained by J.M. Tour(United States), who developed the so-called conver-gentdivergent method to this end. Lengths of 510 nmand the conductivity of self-assembling monolayers(SAMs) adsorbed on the surface of gold electrodes withthiol groups were obtained for molecules of 5 nm inlength. A current density of 50 A/cm

    2

    was reached.An interesting new area is molecular wires with

    insulation. Such conductors are necessary to avoidcross connections in contours. The main approach isencapsulating a conductor in a polymer shell.

    To date, chemistry has achieved wonderful suc-cesses in creating

    nanomaterials

    by the bottomup andtopdown principle. The results obtained in the sphereof nanomaterials are impressive already today.

    Figure 3 shows some materials that are to be intro-duced in less than ten years from now. These are vari-ous ultradisperse catalysts, membrane catalysts, andcarbon nanotube and nanofiber catalysts for variouschemical industries.

    Nanomaterials that are to be introduced later (1020 years from now) are designed for nanoelectronics,nanophotonics, and IT. They are magnetic memorybased on self-organizing magnetic particles, transistorsbased on filled one-wall carbon tubes, and photonicnanocrystals.

    Nanomaterials for biology are mainly at the stage ofbasic research, and their broad introduction is expectedin more than 15 years. Analysis of nanomaterial usesimplies that practically all elements of our life may be

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    related to nanomaterials and nanotechnologies in thefuture.

    A few words about

    coherent chemistry.

    This is anew face of chemistry. Coherence is the property ofchemical systems to form oscillating response modes.Coherence, or response synchrony in time, is a period-ical change in response speed, and it is detected asoscillations in product output, luminescence emission,electrochemical current or potential, etc.

    Chemical coherence exists at two levels: quantumand microscopic. Oscillating and spin coherence is of aquantum origin. The most popular example of macro-scopic coherence is the BelousovZhabotinsky reac-tion.

    Figure 4 shows a quantum oscillating coherence. Ashort laser impulse of 10

    14

    10

    13

    s (its length is smallerthan the oscillation period of atoms) induces a mole-cule and places it in a new potential. A moleculeensemble prepared by a laser impulse behaves coher-ently in this new potential; that is, the atom oscillationsof ensemble members are synchronized, and theensemble itself is a wave packet. As it moves along thepotential surface, the wave packet may fall in severalother packets (with a different oscillation amplitudeand phase); some packets may diphase (lose coherence)and disappear; some may interfere and restore the ini-tial packet; etc.

    Of course, the above picture is simplified, but itclearly illustrates the main ideas of quantum oscillatingcoherence and its chemical effects. The main idea isthat coherent chemistry introduces a new phase factor

    into control over chemical reactions. Changing thephase, we can manipulate the chemical behavior ofensembles of reacting particles without changingmotion energy or momentum.

    Another new sphere of contemporary chemistry is

    spin chemistry,

    which studies the behavior of the angu-lar momenta (spins) of electrons and nuclei in chemicalreactions (Fig. 5). Spin chemistry is based on a funda-mental law: the spin of electrons and nuclei in adiabaticchemical reactions is strictly preserved; only thosereactions are allowed that do not require spin change.

    Ultrafine catalysts

    Carbon nanotubeand nanofiber catalysts

    200 nm

    Al

    2

    O

    3

    Al

    Fig. 3.

    Nanoindustry and the chemical industry.

    6.9

    Na

    I

    Na

    Na

    Na

    +

    Na

    +

    I

    I

    I I

    Ionic state:

    Na

    +

    + I

    Fig. 4.

    Quantum oscillating coherence of wave packet Nal.

    Membrane catalysts

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    In other words, all chemical reactions are spin selec-tive: they are allowed only for the spin states of reagentswhose full spin is the same as product spins, and theyare forbidden if reagent spins differ from product spins.

    We should clearly realize that chemistry is ruled bytwo basic factors: energy and the spin (in coherentchemistry, as was shown in the previous section, a thirdcontrolling factor arises, the phase). Unlike the energyban (which appears when reagent energies are smallerthan the reactions energy barrier), which a reaction canovercome by tunneling under the barrier, the spin ban isinsurmountable.

    Nonchemical magnetic interaction can change thespin; however, they can transform spin-banned (nonre-active) reagent states (e.g., those of radical pairs) intospin-allowed (reactive) states. Being extremely smallenergywise, magnetic interactions switch reactionchannels: they open closed channels and close open(allowed) ones depending on the initial state of thereagents. In fact, they write a new magnetic scenario ofa chemical reaction.

    The spin selectiveness and, consequently, magneticsensitivity of chemical reactions is the source of three

    generations of magnetic effects discovered over thepast two decades. When static magnetic fields (externalor internal fields of magnetic nuclei) induce tripletsin-glet transfers, magnetic effects of the first generationappear. Magnetic effects of the second generationappear when the spin conversion of pairs takes placeunder the influence of microwave fields. Finally, if pairconversion takes place under the influence of the thirdparamagnetic particle, a wonderful phenomenon takesplace: spin catalysis, the third generation of magneticspin effects. In this case, the third particle (a radical ora paramagnetic ion) is a spin catalyst.

    Being selective by the electronic spin, chemicalreactions between spin carriers (radicals, paramagneticions and molecules, carbenes, etc.) are also selective bythe nuclear spin. If both electron-spin and nuclear-spinsubsystems are bound by the Fermi hyperfine interac-tion (FHI), the nuclear subsystem influences the behav-ior of the electron subsystem through FHI and, conse-quently, modifies the chemical reactivity of spin carri-ers. Nuclear-spin selectivity ensures different speeds ofspin-selective reactions of radicals (or other spin carri-ers) with magnetic and nonmagnetic nuclei. This newphenomenon is the magnetic isotopic effect (MIE), dis-covered by Academicians Buchachenko, Yu.N. Molin,Yu.D. Tsvetkov, and Sagdeev, fundamentally differsfrom the classical isotopic effect (CIE), caused by thenuclearmass selectivity of reactions. Both effects sortisotopic nuclei: CIE selects nuclei by their masses, andMIE selects nuclei by their spins and magneticmomenta.

    Figure 6 shows this effect in biochemistry. ATP (amolecular energy carrier) synthesis by enzymes (ATPsynthase and kinases) depends on which magnesiumisotope is in the catalytic site of the enzyme. In the pres-ence of magnetic nucleus

    25

    Mg, ATP output doubles.This discovery serves as the basis for new medicationsagainst hypoxia and cardiac distress. This is just thebeginning. New nuclearmagnetic isotopy promisesgreat discoveries in chemistry and biochemistry.

    The third effect that concerns magnetic effects of thefirst generation is the chemical nuclear polarization(CNP). Unlike MIE, nuclei are sorted here not only bytheir magnetic moments but also by their orientations(Fig. 7). A chemical reaction sends nuclei with differentorientations to different products, creating nonequilib-rium occupancies of nuclear Zeeman levels in theseproducts. The surplus occupancy of the lower Zeemanlevel corresponds to positive nuclear polarization; theoveroccupancy of the higher level, to negative polariza-tion. The latter case is especially noteworthy. When theoveroccupancy of the higher level exceeds a certainadmissible limit, occupancies are inverted; this phe-nomenon underlies chemical radio physics.

    Energy is accumulated in the ensemble of productmolecules with inverse occupancy in the Zeeman reser-voir; this energy may be spent on heat (through spin-lattice relaxation) or it may turn into stimulated radia-

    Fig. 5.

    Spin chemistry.

    Fig. 6.

    Magnetic isotopic effect in ATP synthesis.

    123

    Tripletradical

    pair

    Singletradical

    pair

    Zeeman andFermi

    interaction

    Microwaveand RF

    radiationExchangeinteraction

    First generationof magnetic

    effects

    Second generationof magnetic

    effects

    Third generationof magnetic

    effects

    0.2

    24

    Mg

    ATP yield/min

    0.4

    0.6

    0.8

    1.0

    25

    Mg

    26

    Mg

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    CHEMISTRY IN THE 21st CENTURY: LOOKING INTO THE FUTURE 127

    tion at a Zeeman nuclear frequency. In this case, thereaction becomes a radio frequency emitter and a quan-tum generator with chemical pumping (like chemicallasers). This new phenomenon, RF radiation of a chem-ical reaction, was first predicted theoretically and thendiscovered experimentally.

    As a rule, laboratory-studied chemical reactionsoccur in a narrow interval of temperatures and pres-sures. High and low temperatures and high and super-high pressures open vast opportunities for chemistry.One such discovery and achievement of

    extreme chem-istry

    is metallic hydrogen synthesis, when, as a result ofshock-wave compression, an electron breaks off ahydrogen molecule, forming metalized states with ahigh conductivity of more than 2000 Ohm cm

    1

    . In fact,hydrogen starts to behave like a melt of cesium andrubidium. We may argue whether it is a chemical orphysical result, but the main point is that the electronbreakout and structure transformation are chemicalprocesses. Academician V.E. Fortov performs theseworks at the RAS Institute of Problems of ChemicalPhysics.

    Chemistry in high gravity fields

    may also be referredto extreme reactions. Gravity fields can materiallychange potential gradients and chemical potentials.Such gravity fields are created by centrifugal forces.This is actively being developed in our country by Aca-demician G.A. Abakumov and his school. It opensextremely interesting and promising perspectives forthe development of chemistry in the 21st century.

    Yesterday, at the general meeting of the RASBranch of Chemistry and Materials Sciences, Acade-mician I.N. Fridlyander spoke about the creation ofSoviet centrifuges for uranium-235 separation, whichis only 0.7% of uranium-238. If we use these centri-fuges for chemical reactions in the liquid phase, we cancreate polymer lenses with gradient structures owing tochanges in concentration, and their focal distance willbe determined by the difference of deflections of differ-ent copolymers. In other words, these flat lenses withgradient deflection open good prospects for the devel-opment of optics.

    Low temperatures have always been an object ofchemical studies, and, in the 20th century, Academician

    V.I. Goldanskii and his school showed that the speedsof some chemical reactions at superlow temperatures(around 4 K) cease to be temperature dependent and arepredetermined only by the quantum effects of the reac-tion, when there is no need to overcome the energy bar-rier and quantum effects encourage tunneling and prod-uct formation.

    Chemistry at temperatures of 10

    4

    10

    6

    K should beregarded as exotic. The production of ultracold atomsis based on their changed speed with the absorption ofan optical quantum (laser cooling of atoms). If atomsand laser photons are tuned so that absorption takesplace in the low-frequency area of the spectrum (thered side), such atoms experience a retarding forcedirected along the photon flux. Atoms placed in orthog-onal laser beams are retarded in all three directions; inaddition, an optically viscous medium is created thatstops the movement of atoms, their kinetic temperaturebeing 10

    4

    10

    6

    K (even temperatures of 10

    10

    K can bereached). Ultracold atoms deprived of kinetic energyare of interest for precision spectroscopy and metrologyand for probing the atomatom and atomsurfacepotentials.

    The

    successes of the theory of chemical reactions

    are a special and multifaceted topic. In fact, two largeproblems are solved: the construction of potentialenergy surfaces and the calculation of the movement ofreagent nuclei in estimated potential fields (chemicalact dynamics proper). Both problems are solved in dif-ferent options, at different approximation levels, andwith different accounts for quantum effects. In princi-ple, today we can build potential surfaces with anydegree of accuracy for any reaction (in addition, mod-ern computers can reduce any reaction, no matter howcomplex it is, to a simple one without losing its physicaland chemical contents). Reliable methods have beendeveloped to calculate the dynamic trajectories ofreagent movements on potential surfaces: the methodof classical trajectories (according to the laws of theclassical HamiltonNewtonLagrange mechanics),semiclassical trajectories (accounting for quantumeffects by the superposition of the initial quantum statesof reagents), and purely quantum trajectories (by solv-ing Schrdinger equations and obtaining the probabili-

    Selecting nuclei not only by theirmagnetic momenta but also

    by their orientationsNonequilibrium occupancy

    of Zeeman nuclearlevels

    Stimulated RF radiation

    Fig. 7.

    Chemical polarization of nuclei.

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    ties of reagent transformations on all channels of the S-matrix, or scattering matrix). Speed constants are cal-culated from the totality of trajectories.

    Experimental methods of research into the kineticsof chemical reactions now allow us to obtain a temporalresolution of 1100 fs, which corresponds to a coordi-nate resolution of 0.10.01 . This means that thiscoordinate resolution allows us to monitor the move-ment of nuclei on a potential surface, including the bar-rier apex and vicinity. It is clear that we are speakingabout spectroscopy and transient state chemistry: whathas always been the object of theoretical research hasbecome the subject of experimentation.

    Femtochemis-try

    studies the movement of reacting systems on apotential surface and introduces experimental chemicaldynamics into chemistry.

    The oscillation spectroscopy of a single moleculeaccurately identifies its portrait and allows us to fol-low its dynamics and chemical fate. This opens newprospects for the science of catalysis. The ways ofdetecting the electron paramagnetic resonance of a sin-gle spin are clear and theoretically grounded.

    Atomicresolution chemistry

    is already producing many newideas.

    In conclusion, let us consider

    chemical technologiesin the 21st century.

    These were detailed in the papers byAcademicians G.F. Tereshchenko and V.I. Parmon atthe general meeting of the RAS Branch of Chemistryand Materials Sciences. The hierarchy of structures andrelated regularities of chemical processes are not lim-ited to the levels of electrons and nuclei, atoms andmolecules, and clusters and complexes (nanoparticles).In fact, the diversity of structures and autolocalizationin time and space also continue in the macroworld. The20th century witnessed the creation and wide use ofprocesses in which spatialtemporal distribution wasset by the definite conditions of process organization.Among them are combustion and explosion (self-spreading high-temperature synthesis (SHS), diamondproduction, etc.), as well as chromatography and recti-fication, which have led to a sharp improvement inreaction efficiency, speed, and selectivity. The late20th century showed that such processes are capable ofheat self-localization, the spatial division of chemicaltransformation zones, and the combination of variousspatially divided chemical processes in one reactor.This leads to selectivity and high efficiency and opensbroad prospects for combining various reactions. Thereare grounds to believe that such processes will underliecomplex selective and waste-free processes with anenergy efficiency of 5080%. For example, the process-ing of nontraditional fuels (bitumens, shales, high-ashlignite, etc.) and biofuels based on gasification andpyrolysis in superadiabatic regimes in cooperation withhydrogenation allows us to simultaneously obtain syn-thesis gas, liquid fuels, and nontraditional raw materialsfor the chemical industry.

    A major achievement of the Russian Academy ofSciences is the discovery of the solid flame phenome-non and the creation of the SHS method (AcademicianMerzhanov). Now this progressive field of knowledge,which emerged at the interface of combustion scienceand materials science, has opened nontraditional waysof creating new-generation materials (constructionaland functional ceramics, heatproof intermetallic prod-ucts, etc.).

    As we know, the SHS mode is suitable only forstrong exothermic processes in energy-intensive mediawith a high supply of chemical energy. Recently, Aca-demician Merzhanov proposed another approach tosolve this problem: to conduct a preset low-exothermicreaction in the self-spreading mode. To this end, initialsubstances are selected such that, reacting stage-by-stage, they perform the preset low-exothermic reactionat the final stage, but at a high temperature, which isequivalent to an increased heat effect.

    Finally, let us consider energy supply and energycapacity. These are key issues, of course. The chemicalindustry is among the largest energy consumers. At thesame time, chemists largely contribute to energy pro-duction, and this role of theirs will only intensify as thehydrogen and solar energy industries develop. Thesetwo functions of chemistry largely determine the tasksof chemical science in the energy sphere.

    The 20th century started as a century of coal andplant feed. In the middle of the century, petroleumchemistry emerged, ousting plant feed from a numberof heavy chemistry sectors (for example, potatoes werereplaced by petroleum hydrocarbons in the productionof alcohol and synthetic rubber). At present, we see thatrenewable resources are returning not only to chemistrybut also to the fuel industry. This process is motivatedby both environmental requirements and oil apprecia-tion. Increased oil prices will be not only speculativebut also protective, since oil is a nonrenewableresource.

    The main resource of the high-tonnage chemistry ofthe future is plant feed, which is a complex of cellulose,hemicellulose, and lignin. At present, the foundationhas been laid for two very important engineering andtechnological spheres: the production of biofuel andbioplastics. Chemical and biotechnological methodsconvert plant feed into various energy resources: meth-ane (biogas), hydrogen (biohydrogen), and alcohols(methanol, ethanol, and butanol).

    The transport energy sector is the deepest and mostsensitive sector of the economy. New fuels haveemerged for automobile transport: biogasoline (a bioal-cohol conversion product), biodiesel, biomethane, anddimethyl ether.

    The advantages of the fuel energy industry based onrenewable resources are the use of solar energy as a pri-mary source, considerable and stable renewableresources, and the stabilization of the global carbondioxide level, since biofuel is a product of the photo-

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    CHEMISTRY IN THE 21st CENTURY: LOOKING INTO THE FUTURE 129

    synthetic fixation of carbon dioxide. The prognosticdynamics of development is 20% of the global fuelmarket in 2020 and 50% in 2030.

    Bioplastics are polymer materials obtained bybiomonomer polymerization (polycondensation).Chemical and biotechnological methods allow us toproduce polymer materials with new properties from awide range of monomers recycled from plant feed andwastes. Technologically significant biomonomers areoxyacids, amino acids, and bioolefins.

    Finally, let us say a few words about chemical tech-nologies of the future: they must be fully waste free andconducted in media that do not create environmentalproblems (supercritical media and ionic liquids). Thistrend is followed by Academician V.V. Lunin et al.

    As for the future of chemistry, we would like toquote M.V. Lomonosov: Chemistry is stretching itshands far into human deeds. In the 21st century, therole of chemistry in the life and development of societywill occupy a new level. It is no wonder that the year2011 has been announced as the Year of Chemistry.

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