Traditional Aqueous Routes Advantages Simple Equipment Inexpensive Materials Well Studied Disadvantages Difficult control of hydrolysis and condensation rates Inhomogeneity introduced by homocondensation Reversibility of condensation step Phase Separation M-O-M' + H-O-H ^ »» M-OH + HO-M' 2 M-OH + 2 HO-M' ^ ** M-O-M + M'-O-M' + 2 HOH Nonaquoeus - Nonhydrolytic -Organometallic Methods Advantages Inhomogeneity and phase separation prevented absence of water, volatile organic byproducts cannot cleave M-O-M' bonds and cause homocondensation, irreversible condensation step M = mononuclear, polynuclear clusters, building blocks M-O-X + Z-M' -----* X-Z + M-O-M' Chemical control of reactivity by selecting X, Z groups Wide choice of solvents, medium polarity, reaction temperature Simplified drying to aerogels, lower surface tension Nonaquoeus - Nonhydrolytic -Organometallic Methods Advantages Synthesis of hybrid materials incorporation of water sensitive and water insoluble compounds: organometallics, coordination compounds, long aliphatic chains, clusters hydrophobic hybrid materials Template syntheses use of water sensitive and water insoluble compounds, polymers microporous and mesoporous Retention of lower coordination numbers (Al, TM), low-hydroxyl surfaces - catalysis Nonaquoeus - Nonhydrolytic -Organometallic Methods Disadvantages - Elaborate procedures and expensive precursors - Organic solvents - Exclusion of moisture - Ligand scrambling vs. elimination Nonaquoeus - Nonhydrolytic -Organometallic Methods Solid-state: solid-state thermolysis Liquid-state: sol-gel, solventless, sonochemical reactions, solution thermolysis Gas-phase: CVD, pyrosol Preparation of Oxides, Mixed Oxides, and Silicates Alkylhalide Elimination Ether Elimination Ester Elimination Ketene Elimination Alkene Elimination Ketimine Elimination Acetamide Elimination Alkylhalide Elimination Reactions M = Si, Al, Ti, Zr, V, Nb, Mo, W, Fe M-X + R-O-M' --------->• M-O-M' + R-X M-X + R-O-R --------->► M-O-R + R-X M-O-R + X-M' --------->• M-O-M' + R-X M-X + H-O-R --------->• M-O-R + HX M-O-R + X-M' --------->• M-O-M' + R-X Corriu, Vioux, Leclercq, Mutin, Montpellier Hay et al., Surrey Alkylhalide Elimination Reactions OR M. R X)' X- \/ X i M X X OR RO-^M\. 'R RO^ X- O ■M- RO- -X -RX 4\ X X x C-O bond cleavage OR Ro/vR RO X----------M- X X -X OR RO-^M\ Ro' ? .R .M, % ''».. * | -x X © X 0 OR RO'^ \_____R RO' P C; X-----------M; X 4\ X X RO- OR •M RX / x ? -x x OR 0 RO-^M\ Ro' C RX R .© X-----------M- -X X X Alkylhalide Elimination Reactions heptadecane 300 °C TiCI4 + Ti(OR)4 + TOPO ------------► Ti02anatase 10 nm R = Me, Et, /-Pr, ř-Bu + RCI Colvin et al., J. Am. Chem. Soc., 1999,121, 1613 Alkylhalide Elimination Reactions CCI4, 110 °C AICI3 + Si(OEt)4 + Et20 --------------► Al-O-Si gel 900 °C T 3AI203 2Si02 mullite Janackovic et al., NanoStructured Materials, 1999,12, 147 Alkylhalide Elimination Reactions ci '■^'"•■ci ' *0 Mr"-o o r \ Si Si Tilley et al., Berkely H. .H \ + |_|Q...ui\\ll!S O« IAI ^HO •ObH O uopmnunjg u9§oipÁfj-£| sa;BiouBiis(Áxo;nq-;ja;)m; :uoi}Buiuiiig aua^iy AcO Acetamide Elimination AcO J O O- kO AcO + O •Si' Me2 N \ O / Me2N Me2N-., "JI/M Art |U\\*-NMe2 Me2N^ \ / ^NMe2 Me2 0 gel 950 °C Pinkas J., Lobl J., Roesky H. W. unpublished T 3AI203.2Si02 mullite Ether Elimination M /-^ -x M^ ^M" cr ^d ^o R + M'- R ■o* R ■O' R Hampden-Smith et al., Ketene Elimination Bu R O .Al Et H ))))), 10 min decane OH ,AI, R' "OH H Bu Et + c^=c^=o gel CN(AI) = 6 Ulman et al., J. Am. Chem. Soc, 2003, 725, 4010 700 - 900 °C > ~ w»»5 * -"-' ; Y-AI2O3 (10 nm) Y3AI5O12 LaAI03 Ketimine Elimination Et Et H2N ^NH2 Et--------Al^ Al--------Et /^n^ \ Et H2 Et + EtH + EtAlO NH HoO - EtH Lindquist et al., Chem. Mater., 2003,15, 51 AIO(OH) high porosity Thermolysis of a single-source precursor R2 N /pro. / \ TOPO 325 °C /pro*^Ti / _____________*► TÍO2 anatase /-PrO O 3 nm Fischer et al., J. Mater. Chem. 2002, 72, 1625 Preparation of Phosphates and Phosphonates Alkane/Hydrogen Elimination Alkene Elimination Alkylhalide Elimination Alkylsilane Elimination Aklylamine Elimination Alcohol Elimination Ether Elimination Chlororsilane Elimination Diketone/Ester Route Alkane/Hydrogen Elimination Schmidt et al., J. Polym. Sei. A, 1968, 6, 3235 -o Et2AIF o .Al O *cr R + EtH J n R = Me, Ph, A7-Oct, A7-Dodec o- OH H2AICI(THF): R X> Me2Zn ci o .Al O xr R + H- J n Gerbier et al., J. Mater. Chem. 1999, P, 2559 Knight et al., J. Organometal. Chem. 1999, 585, 162 (RP03)Zn + 2MeH layered R = Me, Ph, thienyl, Me-thiophenyl Alkene Elimination er ^o V Y /v AIPO4 + XH + X = Me, O'Pr X = SifO^u). AI2P2Si3014 Tilley et al., J. Am. Chem. Soc. 2001,123, 10133 Alkene Elimination: ŕrá(tert-butoxy)silanolates Bu'o BiilO^ \ o'Bu I -Si O'Bu -O'Bu Bu'° f-^-r^ \ o \ Al Al—cjr— P ,' V° ^O—AL H20 isobutene \ Si—o'Bu 0:Bu "Al / Cio-^ O \ Al Al \ O Al—nm—P °' Im Pw 1 O Si02 iy- rAI AI O V I ^*PH Pinkas J., Brlejova Z., Roesky H. W. unpublished Alkene Elimination: ŕrá(tert-butoxy)silanolates TO/% isobutene + H20 i________i________i________i________i________i________i________i________i 0 100 200 300 400 500 600 700 800 Temperature/°C ZV I- Alkylhalide Elimination Nonhydrolytic synthesis of NASICON Na3Zr2Si2P012 solid electrolyte, high Na+ ionic conductivity - Solid state preparation: dissolved Zr02 - Sol-gel from alkoxides: very slow hydrolysis necessary, different hydrolysis rates - Nonhydrolytic route in CI-LCN 3 Bu tBu OP(OnBu)3 + SiCI4 + Zr(OťBu)4 + NaO'Bu -> nBuCI + ťBuCI + ^ CIO III. B u-O—P-O—S i-O-Zr-O-tB u II I I O CI O Gel formation ' Solvent and byproduct evaporation under vacuum Drying at 120 °C for 15 h Ball milling Di Vona et al., J. Sol-Gel Sei. TechnoL, 2000, 7/3, 463 Calcination at 800 C gives NASICON '5 ^ ' " 5 Ether Elimination Me3Si Me \ Me.......IAľ / O. í -Pr .Aľ ^SiMe3 A*Me Me3Sľ i Me rSiMe3 CF3CH2OH CF3CH2OSiMe2 Me Me.......IAI — / °\ HO^— P------ OH .Aľ O /^*Me i OH Me Pinkas J., Moravec, Z., Roesky H. W. unpublished CH3-AIPO4 gel Chlororsilane Elimination THF, reflux AICI3 + OP(OSiMe3)3 -------------► gel AIPO4+ CISiMe3 800 °C Pinkas J., et al. Inorg. Chem. 1998,37,2450 AIPO4 tridymite 13% Si Diketone/Ester Route .o Al + pyrosol CVD process inethanol, 300-400 °C ^ AIPO4 amorphous .OR 0=P