Bifunctional Water Activation for Catalytic Hydration of Organonitriles

Supporting Information (16 pages including the cover page) Bifunctional Water Activation for Catalytic Hydration of Organonitriles Prosenjit Daw, Arup Sinha, S. M. Wahidur Rahaman, Shrabani Dinda and Jitendra K. Bera* Department of Chemistry Indian Institute of Technology Kanpur Kanpur 208016, India Table S1. Important bond distances and bong angles for 1. Computational details Table S2 S9. Atomic coordinates of the intermediates A G and the transition state TS-CD References S2 S3 S4-S15 S16 S1

Table S1. Important bond distances and bong angles for 1. Bond Length (Å) Rh1 C33 2.016(6) N2 C30 1.327(7) Rh1 C2 2.103(6) C22 N1 1.320(7) Rh1 C1 2.118(6) N4 C33 1.360(7) Rh1 C5 2.211(7) N4 C32 1.393(7) Rh1 C6 2.216(6) N4 C34 1.478(7) Rh1 Br1 2.5123(8) N3 C33 1.385(7) Rh1 H29 2.7304 N3 C31 1.400(7) C27 N1 1.375(7) N3 C30 1.429(7) C27 N2 1.382(7) C1 C2 1.369(10) C2 C3 1.511(9) Bond Angle ( ) C33 Rh1 Br1 89.98(15) C33 Rh1 C1 91.9(2) C33 Rh1 C2 87.8(2) C33 Rh1 C5 158.8(2) C33 Rh1 C6 164.7(2) N4 C33 N3 103.2(4) N3 C33 Rh1 131.4(4) C33 N3 C31 111.2(4) C33 N4 C32 111.8(4) C33 N3 C30 124.7(5) S2

Computational details Full geometry optimization and frequency calculations were performed at the gradient-corrected DFT level using the three parameter fit of the exchange-correlation potential suggested by Becke, in conjunction with the correlation functional suggested by Lee, Yang, and Parr (B3LYP) 1 as implemented in Gaussian 03. 2 The structures reported are either minima (number of imaginary frequency = 0) or transition state (number of imaginary frequency = 1) on the potential energy surface. The double-ζ basis set of Hay and Wadt (LanL2DZ) with effective core potential (ECP) 3 was used for the Rh. The ligand atoms H, C, N and O atoms were described using the 6-31G(d,p) basis sets. 4 Solvent effects were accounted using acetronitrile (ε = 36.64) taking optimized geometries from gas phase calculations with a polarisable continuum model (PCM). 5 S3

Intermediate A Energy = -1236.576115 Hartee (in acetrolitrile) Table S2. XYZ coordinates of the intermediate A. Atom X Y Z Rh 1.07480-0.28528 0.06840 C 1.24815-0.69703-2.02483 H 0.83656 0.13888-2.58888 N -1.52895 0.50936 0.09237 C -0.05008 3.73647-0.59440 H -0.85098 4.43435-0.76978 N -2.68975-1.37376 0.76053 C -1.50421 1.69146-0.48279 C -5.06674-1.58483 0.32999 H -5.95552-2.19633 0.44084 N 1.85911 2.71190-0.16577 C -3.91040 0.38667-0.41373 C 0.94211 1.71577-0.20189 N -0.24814 2.35899-0.46471 C 1.27065 3.95185-0.40659 H 1.84008 4.86800-0.41247 C -3.82688-2.04151 0.84270 C -3.82709 1.65205-1.04577 H -4.71382 2.08747-1.49749 C 0.49322-2.50031 0.09973 H -0.25064-2.48489 0.89342 C -2.71315-0.16446 0.14195 C -5.10608-0.36566-0.30362 C -2.62519 2.31447-1.08996 H -2.53458 3.26987-1.59156 C 2.54520-0.48630-1.48173 H 2.99268 0.48297-1.69528 C 2.97118-2.80852-0.48962 H 2.62938-3.51450-1.25103 H 3.75361-3.32686 0.07394 C 0.68603-2.06156-2.42778 H 1.49357-2.68535-2.82518 S4

H -0.01190-1.92263-3.25934 C 3.57221-1.55152-1.15166 H 4.30640-1.10540-0.47094 H 4.13118-1.82877-2.05872 C -0.05408-2.79328-1.28244 H -1.10407-2.48876-1.28160 H -0.05222-3.87834-1.46240 C 1.82501-2.47703 0.44840 H 2.06788-2.42992 1.50701 C 3.27890 2.54286 0.13952 H 3.44015 1.51205 0.44987 H 3.88898 2.76752-0.73951 H 3.55882 3.21691 0.95277 H -6.03017 0.02877-0.71715 H -3.78018-3.00717 1.34315 N 1.01106-0.02953 2.23798 C 0.90499 0.02262 3.39011 C 0.77100 0.08060 4.84096 H 0.24422-0.80725 5.20185 H 1.75874 0.12129 5.30868 H 0.20425 0.97002 5.12982 Intermediate B Energy = -1313.015005 Hartee (in acetrolitrile) Table S3. XYZ coordinates of the intermediate B. Atom X Y Z Rh 1.39595-0.23952-0.08846 C 0.57856-0.61154-2.06945 H -0.14998 0.17052-2.27294 N -1.79517 0.59016 0.43787 C -0.21273 3.73109-0.04297 H -1.07319 4.37944-0.01967 N -3.18212-1.16621 1.03928 C -1.58264 1.67539-0.27008 C -5.41689-1.36565 0.12605 H -6.33967-1.93485 0.10735 N 1.77818 2.79101 0.01928 C -4.02431 0.47071-0.56036 S5

C 0.91823 1.74614-0.08307 N -0.32373 2.33910-0.12185 C 1.10667 4.00815 0.05053 H 1.62292 4.95064 0.14445 C -4.34279-1.79066 0.94557 C -3.74506 1.64506-1.30113 H -4.49362 2.04740-1.97765 C 1.10017-2.48896 0.07829 H 0.82059-2.55952 1.12814 C -3.00151-0.03695 0.30037 C -5.25446-0.23020-0.63026 C -2.52087 2.25132-1.16799 H -2.25979 3.13028-1.74541 C 1.93021-0.23604-2.18510 H 2.12465 0.79606-2.47472 C 3.03815-2.48808-1.61370 H 2.47219-3.23628-2.17466 H 4.05038-2.89150-1.51100 C 0.04829-2.03531-2.22413 H 0.65552-2.57254-2.95875 H -0.95900-1.99028-2.65028 C 3.11115-1.16131-2.40415 H 4.01581-0.61831-2.10839 H 3.22322-1.36692-3.47968 C -0.01518-2.81902-0.89198 H -0.95678-2.58955-0.38388 H -0.03016-3.90064-1.09109 C 2.43280-2.31636-0.23149 H 3.13532-2.26340 0.59713 C 3.23386 2.67292 0.09409 H 3.49553 1.62008-0.00452 H 3.69567 3.24678-0.71326 H 3.59095 3.04896 1.05629 H -6.04613 0.13796-1.27683 H -4.45442-2.68863 1.55013 N 1.89095-0.12506 1.97286 H -1.65737-1.62383 2.50119 O -0.78692-1.26940 2.74145 H -0.74304-0.51327 2.13631 C 1.86861-0.28211 3.12007 C 1.75379-0.52037 4.55006 H 1.87984 0.41090 5.10846 H 0.75070-0.92575 4.71736 H 2.50644-1.24242 4.87792 S6

Intermediate C Energy = -1313.009707 Hartee (in acetrolitrile) Table S4. XYZ coordinates of the intermediate C. Atom X Y Z Rh 1.23551-0.33097-0.05200 C 0.18081-0.92522-1.78571 H -0.63116-0.23407-2.00698 N -1.97389 0.66224 0.60288 C -0.42125 3.61616-0.57910 H -1.27498 4.27227-0.61989 N -3.22863-0.99113 1.59815 C -1.81675 1.59809-0.30029 C -5.53818-1.34585 0.95349 H -6.44494-1.91751 1.11809 N 1.56400 2.66826-0.48165 C -4.26617 0.36450-0.15627 C 0.69873 1.63585-0.29445 N -0.54368 2.24012-0.36624 C 0.90115 3.87893-0.64461 H 1.42809 4.80981-0.78317 C -4.37784-1.63163 1.71780 C -4.06418 1.39708-1.10613 H -4.87412 1.68290-1.77124 C 1.21664-2.60453 0.31418 H 1.16077-2.64077 1.39933 C -3.16538 0.00721 0.67941 C -5.48068-0.34765 0.00992 C -2.83743 2.01104-1.19707 H -2.64073 2.77083-1.94403 C 1.48806-0.46520-2.15236 H 1.52758 0.52610-2.60533 C 2.83029-2.59199-1.68347 H 2.23310-3.41570-2.08293 H 3.87172-2.92714-1.72302 C -0.25175-2.39479-1.78032 H 0.25399-2.93393-2.58825 S7

H -1.31934-2.45263-2.01538 C 2.66545-1.33169-2.55691 H 3.57221-0.72066-2.47804 H 2.58406-1.61114-3.61842 C -0.01299-3.09598-0.42340 H -0.87670-2.91145 0.22427 H 0.03879-4.18652-0.55752 C 2.45142-2.34755-0.23491 H 3.27191-2.16259 0.45329 C 3.02128 2.56056-0.54790 H 3.28816 1.50907-0.62150 H 3.38203 3.10013-1.42664 H 3.47261 2.98821 0.35085 H -6.34062-0.09988-0.60597 H -4.40911-2.42859 2.45837 N 2.70342 0.20659 1.61292 C 3.25303 0.34917 2.62200 C 3.92314 0.52001 3.90584 H 3.22177 0.30466 4.71688 H 4.77484-0.16168 3.98082 H 4.28226 1.54732 4.01198 H -0.41731-1.25950 2.40033 O -0.00285-0.40984 2.19721 H -0.74287 0.08331 1.77568 Transition State TS-CD Energy = -1312.977809 Hartee (in acetrolitrile) Table S5. XYZ coordinates of the TS-CD. Atom X Y Z Rh 1.39122-0.29469 0.10861 C 0.86907-1.12953-1.87001 H 0.17320-0.44194-2.34886 N -1.81316 0.70752 0.18886 C -0.12210 3.53069-1.10572 H -0.95280 4.14486-1.41310 N -3.22832-0.73578 1.29662 S8

C -1.47847 1.47572-0.84256 C -5.30671-1.44107 0.27113 H -6.20752-2.03648 0.36906 N 1.79715 2.67965-0.41259 C -3.86801 0.07018-0.92493 C 0.94722 1.62650-0.35779 N -0.26295 2.17249-0.77353 C 1.17050 3.83764-0.86650 H 1.69509 4.77524-0.96465 C -4.35795-1.42593 1.32349 C -3.50211 0.90630-2.00898 H -4.15604 0.98188-2.87288 C 1.07242-2.46597 0.70455 H 0.66673-2.35347 1.70726 C -2.98396-0.00651 0.18755 C -5.06298-0.68970-0.85532 C -2.31702 1.60556-1.97276 H -1.99799 2.22727-2.80036 C 2.21656-0.74277-1.87498 H 2.44728 0.20848-2.35404 C 3.24037-2.75890-0.64842 H 2.77011-3.63575-1.10199 H 4.22764-3.08940-0.31024 C 0.37257-2.57120-1.76872 H 1.08217-3.23649-2.26951 H -0.56107-2.66391-2.33414 C 3.42448-1.64218-1.70142 H 4.26581-1.00757-1.40059 H 3.71122-2.08196-2.66886 C 0.12001-3.05064-0.31838 H -0.89525-2.76811-0.01852 H 0.14898-4.14986-0.27804 C 2.43502-2.30965 0.55822 H 2.99934-2.04038 1.44722 C 3.21611 2.60636-0.05599 H 3.49463 3.51210 0.48654 H 3.36158 1.73632 0.58321 H 3.83142 2.51636-0.95511 H -5.76529-0.66636-1.68326 H -4.54247-2.00835 2.22331 N 1.49829 0.21475 2.08569 C 0.64135 0.51873 2.90924 C 0.72453 0.79438 4.38462 H 0.39537 1.81335 4.61153 H 0.08872 0.10791 4.95742 H 1.75579 0.66269 4.71264 O -0.82715 0.76374 2.48050 H -1.44865 0.25486 3.02603 H -1.21820 0.69134 1.22507 S9

Intermediate D Energy = -1312.981649 Hartee (in acetrolitrile) Table S6. XYZ coordinates of the intermediate D. Atom X Y Z Rh 1.32466-0.21790 0.04192 C 0.82146-1.40082-1.83052 H 0.03387-0.85805-2.35004 N -1.71141 0.30337-0.21620 C -0.32624 3.54495-1.19467 H -1.14974 4.18777-1.44859 N -2.74999-1.62306 0.53028 C -1.68534 1.52707-0.75069 C -5.15664-1.84580 0.37228 H -6.02403-2.46815 0.56125 N 1.63578 2.66124-0.68002 C -4.10771 0.16365-0.42841 C 0.78312 1.62090-0.53933 N -0.46644 2.18047-0.85780 C 0.98486 3.82518-1.07932 H 1.51204 4.75290-1.23882 C -3.86764-2.31068 0.72239 C -4.08092 1.45320-1.01960 H -5.01036 1.90840-1.34920 C 1.25189-2.37412 0.90114 H 0.85067-2.16876 1.89057 C -2.87215-0.41085-0.02891 C -5.27706-0.60297-0.20977 C -2.89706 2.12707-1.18262 H -2.88515 3.10194-1.64791 C 2.10620-0.86651-1.93882 H 2.20965 0.03895-2.53586 S10

C 3.39270-2.57672-0.49711 H 3.01512-3.54960-0.82331 H 4.42200-2.74839-0.16610 C 0.50769-2.86246-1.51973 H 1.27641-3.49407-1.97506 H -0.42727-3.13301-2.02208 C 3.41696-1.58614-1.68537 H 4.18138-0.82391-1.49526 H 3.73897-2.10920-2.59867 C 0.36332-3.19126-0.01189 H -0.67015-3.01028 0.29218 H 0.55168-4.26329 0.14962 C 2.57707-2.08054 0.68364 H 3.12572-1.62064 1.50093 C 3.07354 2.57648-0.39998 H 3.21151 1.98162 0.50363 H 3.59698 2.11322-1.23960 H 3.45735 3.58629-0.24688 H -6.24446-0.20426-0.50018 H -3.75051-3.29106 1.17812 N 1.63786 0.53728 1.89259 C 0.79708 0.86076 2.76502 O -0.59193 0.77958 2.55003 H -0.77112-0.11692 0.09339 C 1.15609 1.37717 4.14540 H 0.76929 0.71083 4.92691 H 2.23911 1.43512 4.24551 H 0.73002 2.37331 4.32022 H -1.05115 1.01752 3.36809 Intermediate E Energy = - 1313.018495 Hartee (in acetrolitrile) Table S7. XYZ coordinates of the intermediate E. Atom X Y Z Rh 1.32238-0.27071 0.19216 C 1.22653-1.27306-1.80470 H 0.49607-0.72541-2.39771 S11

N -1.70865 0.17457-0.24671 C -0.36124 3.34944-1.43794 H -1.17140 3.91491-1.86151 N -2.71325-1.71968 0.61130 C -1.68010 1.34435-0.89583 C -5.10204-2.03790 0.37177 H -5.95791-2.67072 0.57741 N 1.56361 2.62084-0.62777 C -4.08260-0.06790-0.55581 C 0.74162 1.56407-0.46384 N -0.47851 2.00727-1.01399 C 0.90621 3.71543-1.18973 H 1.40518 4.65541-1.36665 C -3.81776-2.42821 0.81373 C -4.06109 1.16742-1.25775 H -4.98697 1.56513-1.66293 C 1.25921-2.47150 0.85157 H 0.68631-2.40787 1.77355 C -2.85331-0.56424-0.05366 C -5.23519-0.85292-0.32064 C -2.89085 1.86012-1.43233 H -2.88840 2.79347-1.97581 C 2.47319-0.65788-1.64782 H 2.61108 0.29928-2.14918 C 3.62270-2.42029-0.16161 H 3.38066-3.38405-0.61711 H 4.58974-2.55735 0.33241 C 0.96864-2.77335-1.68799 H 1.84778-3.32003-2.04172 H 0.16018-3.04494-2.37475 C 3.77207-1.33281-1.25064 H 4.45259-0.55531-0.88457 H 4.26042-1.75929-2.13973 C 0.57949-3.23632-0.26454 H -0.49881-3.11207-0.12755 H 0.78011-4.31229-0.15246 C 2.58081-2.08209 0.89284 H 2.96647-1.71535 1.84201 C 2.93195 2.69269-0.11899 H 3.28481 1.67934 0.06636 H 3.57197 3.18292-0.85601 H 2.94779 3.25587 0.81804 H -6.20095-0.51520-0.68446 H -3.69136-3.36239 1.35549 N 0.91463 0.29355 2.11895 C 0.21220 1.36588 2.53333 O -0.31743 2.18120 1.75284 H -0.79558-0.20444 0.12668 H 1.25358-0.28149 2.88229 C 0.05636 1.58568 4.03573 H -1.00829 1.59037 4.28677 H 0.56189 0.83442 4.64776 H 0.44954 2.57397 4.29003 S12

Intermediate F Energy = -1313.035434 Hartee (in acetrolitrile) Table S8. XYZ coordinates of the intermediate F. Atom X Y Z Rh 1.19711-0.39974 0.11319 C 0.90973-1.31466-1.83560 H 0.29942-0.63445-2.42677 N -1.63938 0.50397 0.02964 C -0.05550 3.36441-1.45772 H -0.86228 3.99976-1.78247 N -2.89730-1.08042 1.14140 C -1.52211 1.41542-0.90592 C -5.21706-1.46496 0.54540 H -6.12276-2.02506 0.75122 N 1.85612 2.46261-0.83023 C -3.95333 0.17983-0.66791 C 0.93704 1.49194-0.60586 N -0.25251 2.05648-1.00659 C 1.26770 3.61496-1.34336 H 1.83816 4.50054-1.57582 C -4.04771-1.70726 1.30999 C -3.77548 1.16714-1.66906 H -4.59879 1.41534-2.33298 C 0.76495-2.51230 0.78923 H 0.22647-2.35167 1.72205 C -2.83343-0.13619 0.16455 C -5.16706-0.51828-0.44977 C -2.55814 1.78837-1.80363 H -2.38620 2.51744-2.58629 C 2.26535-0.95738-1.68558 H 2.58242-0.04749-2.19368 C 3.07114-2.93527-0.26939 H 2.62187-3.82207-0.72418 H 3.99700-3.27646 0.20462 C 0.36700-2.73938-1.73895 S13

H 1.11327-3.44083-2.12500 H -0.49680-2.83293-2.40467 C 3.41373-1.88834-1.35044 H 4.24868-1.27172-0.99867 H 3.77163-2.38770-2.26377 C -0.06824-3.13944-0.30945 H -1.10121-2.82159-0.14440 H -0.06300-4.23468-0.20588 C 2.14140-2.38762 0.80119 H 2.62010-2.11884 1.74158 C 3.28132 2.34924-0.53179 H 3.45891 1.36433-0.10153 H 3.87075 2.46781-1.44495 H 3.57258 3.11974 0.18711 H -6.03361-0.29853-1.06746 H -4.07313-2.45899 2.09721 N 1.16812 0.24269 2.19252 C 0.75078 1.26715 2.84092 C 0.61391 1.35083 4.33850 H 1.21068 2.18193 4.73052 H -0.43337 1.52948 4.60802 H 0.93977 0.43118 4.82574 O 0.40982 2.36456 2.14539 H 0.08476 3.05126 2.74304 H 1.40493-0.51091 2.83121 Intermediate G Energy = -1313.041764 Hartee (in acetrolitrile) Table S9. XYZ coordinates of the intermediate G. Atom X Y Z Rh 1.08763-0.44453 0.13589 C 1.22983-1.25126-1.86431 H 0.75776-0.54163-2.54170 N -1.68356 0.62196 0.09338 C -0.04395 3.28605-1.59258 S14

H -0.83043 3.88576-2.02078 N -2.94545-0.77144 1.41347 C -1.52603 1.35555-0.98395 C -5.20934-1.35816 0.77690 H -6.10720-1.90793 1.03706 N 1.81586 2.45782-0.73474 C -3.93389 0.08755-0.65877 C 0.90006 1.47399-0.56474 N -0.25938 1.99978-1.09311 C 1.25874 3.56963-1.36285 H 1.83238 4.45826-1.57514 C -4.08357-1.40453 1.63883 C -3.72157 0.89421-1.80614 H -4.51138 0.99529-2.54500 C 0.53870-2.59148 0.59637 H -0.18572-2.48502 1.40328 C -2.86105-0.02849 0.27698 C -5.13456-0.61135-0.37549 C -2.51452 1.53168-1.98394 H -2.31653 2.12951-2.86613 C 2.51992-0.90477-1.40363 H 2.92849 0.02926-1.78549 C 3.02742-2.95851 0.04578 H 2.70620-3.82438-0.53905 H 3.83350-3.31528 0.69402 C 0.69670-2.67962-1.96513 H 1.51905-3.35741-2.21317 H 0.00116-2.73808-2.80790 C 3.57963-1.85302-0.88064 H 4.31395-1.25674-0.32765 H 4.12854-2.30145-1.72238 C -0.03298-3.15698-0.68808 H -1.08267-2.85057-0.74000 H -0.04066-4.25576-0.64419 C 1.87855-2.47405 0.91300 H 2.13686-2.25348 1.94758 C 3.20605 2.40100-0.27661 H 3.34329 1.48318 0.29240 H 3.88760 2.42083-1.13088 H 3.41062 3.25462 0.37302 H -5.97287-0.54791-1.06363 H -4.13497-1.99266 2.55307 C 0.93480 1.42082 2.68203 C -0.10763 2.51307 2.66005 H -0.67678 2.46926 3.59656 H 0.38478 3.48418 2.60658 H -0.81457 2.38367 1.83788 O 2.08933 1.58002 3.01109 N 0.47642 0.12290 2.28802 H 0.93442-0.59101 2.84867 H -0.53799 0.00407 2.26177 S15

References (1) (a) Becke, A. D. J. Chem. Phys. 1993, 98, 5648. (b) Lee, C.; Yang, W.; Parr, R. G.; Phys. Rev. B 1998, 37, 785. (2) Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A., Jr.; Vreven, T.; Kudin, K. N.; Burant, J. C.; Millam, J. M.; Iyengar, S. S.; Tomasi, J.; Barone, V.; Mennucci, B.; Cossi, M.; Scalmani, G.; Rega, N.; Petersson, G. A.; Nakatsuji, H.; Hada, M.; Ehara, M.; Toyota, K.; Fukuda, R.; Hasegawa, J.; Ishida, M.; Nakajima, T.; Honda, Y.; Kitao, O.; Nakai, H.; Klene, M.; Li, X.; Knox, J. E.; Hratchian, H. P.; Cross, J. B.; Adamo, C.; Jaramillo, J.; Gomperts, R.; Stratmann, R. E.; Yazyev, O.; Austin, A. J.; Cammi, R.; Pomelli, C.; Ochterski, J. W.; Ayala, P. Y.; Morokuma, K.; Voth, G. A.; Salvador, P.; Dannenberg, J. J.; Zakrzewski, V. G.; Dapprich, S.; Daniels, A. D.; Strain, M. C.; Farkas, O.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Ortiz, J. V.; Cui, Q.; Baboul, A. G.; Clifford, S.; Cioslowski, J.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Gonzalez, C.; Pople, J. A. Gaussian 03; Gaussian, Inc.: Pittsburgh, PA, 2003. (3) (a) Hay, P. J.; Wadt, W. R.; J. Chem. Phys. 1985, 82, 270. (b) Wadt, W. R.; Hay, P. J. J. Chem. Phys. 1985, 82, 284. (c) Hay, P. J.; Wadt, W. R. J. Chem. Phys. 1985, 82, 299. (4) (a) Binkley, J. S.; Pople, J. A.; Hehre, W. J. J. Am. Chem. Soc. 1980, 102, 939. (b) Hehre, W. J.; Ditchfield, R.; Pople, J. A. J. Chem. Phys. 1972, 56, 2257. (5) (a) Tomasi, J.; Persico, M. Chem. Rev. 1994, 94, 2027. (b) Barone, V.; Cossi, M. J. Phys. Chem. A 1998, 102, 1995. S16