Supporting Information

Dimetallaheteroboranes containing group 16 elements: A combined experimental and theoretical study

KIRAN KUMARVARMA CHAKRAHARI, RONGALA RAMALAKSHMI, DUDEKULA SHARMILA andSUNDARGOPAL GHOSH*

Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India. e-mail:

Contents:

IDFT Calculations

IISupplementary Data

  1. Table S1Selected bond parameters for the optimized geometries [(CpM)2B5H9Fe(CO)3], 4a-6a: (Cp analogues of [(Cp*Mo)2B5H9Fe(CO)3], 4-6 respectevily)at B3LYP/def-TZVP level of theory
  2. Table S2DFT calculated (B3LYP/def-TZVP level) energies of the HOMO and LUMO (eV) and HOMO-LUMO gaps (E = ELUMO-EHOMO, eV) for the clusters [(CpM)2B5H9Fe(CO)3], 4a, 5a and 6a.
  3. Table S3DFT calculated and experimental 11B and 1H NMR chemical shifts δ (ppm) and IR (cm-1) stretching values for [(CpM)2B5H9Fe(CO)3],and 4a-6a.
  4. Figure S1Localized molecular orbital (LMO)representation: (a) Bonding interaction between Mo-Mo and (b) Antibonding interaction between Mo-Mo.
  5. Figure S2Optimized structure of [(CpM)2B5H9Fe(CO)3], at B3LYP/def2-TZVP level of theory
  6. Figure S3Optimized structure of 4a(4a: Cp analogue of 4) at B3LYP/def2-TZVP level of theory
  7. Figure S4Optimized structure of 5a(5a: Cp analogue of 5) at B3LYP/def2-TZVP level of thoery
  8. Figure S5Optimized structure of 6a (6a: Cp analogue of 6) at B3LYP/def2-TZVP levelof theory

IDFT Calculations:

The density functional theory (DFT)1 calculations were carried out on the model compounds [(CpM)2B5H9Fe(CO)3], 4a, 5a and 6a (Cp analogues of (Cp*Mo)2B5H9Fe(CO)3, 4, 5 and6)as implemented in Gaussian092 program package. To reduce computing time all the calculations were carried out with the Cp analogue model compounds, instead of Cp*.The full geometry optimizations has been carried out with the Becke-3 parameter exchange and the Lee-Yang-Parr correlation functional (B3LYP)3-6density functional level of theory, in conjunction with def2-TZVPbasis set from EMSL Basis Set Exchange Library in the gas phase (no solvent effect)without any symmetry constraints. The 28 core electrons of molybdenum were replaced by the quasi-relativistic effective core potential, def2-ECP7. The frequency calculations were conducted to determine if each stationary point corresponds to a minimum on the potential energy surface (PES). The crystallographic parametrs has been used as a starting geometry for complete geometry optimizations. We also calculated NMR shielding tensors at the B3LYP/GIAO8 level of theory.The 11B NMR chemical shifts were calculated relative to B2H6 (B3LYP B shielding constant 93.5 ppm) and converted to the usual BF3.OEt2 scale using the experimental δ(11B) value of B2H6, 16.6 ppm9 and TMS (SiMe4) was used as internal standard for the1H NMR chemical shift calculations (B3LYP 1H shielding constant 31.92 ppm).Further, natural bond orbital (NBO)10analysis was carried out at same level theory. From NBO analysis Wiberg bond indexes (WBI)11 were obtained. Molecular structure and molecular orbital images were generated with Gauss view program.

IISupplementary Data

Table S1.Selected bond parameters for the optimized geometries [(CpM)2B5H9Fe(CO)3],(4a-6a) (Cp analogues of [(Cp*Mo)2B5H9Fe(CO)3], 4-6 respectevily)at B3LYP/def2-TZVP level of theory.

Bond lengths (Å)
Atom Pair / (CpMo)2B5H9Fe(CO)3 / 4a / 5a / 6a
Exp. / Cal. / Exp. / Cal. / Exp. / Cal. / Exp. / Cal.
Mo1-Mo2 / 2.941 / 2.971 / 2.885 / 2.920 / 2.919 / 2.947 / 2.952 / 2.982
Mo1-B1 / 2.364 / 2.374 / 2.259 / 2.285 / 2.292 / 2.285 / 2.260 / 2.284
Mo1-B2 / 2.157 / 2.160 / 2.317 / 2.321 / 2.361 / 2.322 / 2.322 / 2.323
Mo1-B3 / 2.309 / 2.318 / 2.124 / 2.125 / 2.154 / 2.127 / 2.144 / 2.131
Mo2-B1 / 2.273 / 2.285 / 2.252 / 2.286 / 2.261 / 2.285 / 2.262 / 2.284
Mo2-B2 / 2.355 / 2.374 / 2.317 / 2.317 / 2.413 / 2.322 / 2.314 / 2.323
Mo2-B4 / 2.154 / 2.160 / 2.132 / 2.125 / 2.164 / 2.127 / 2.161 / 2.132
Mo1-Fe / 2.298 / 2.318 / 2.752 / 2.780 / 2.791 / 2.804 / 2.798 / 2.837
Mo2-Fe / 2.258 / 2.285 / 2.763 / 2.780 / 2.796 / 2.804 / 2.814 / 2.837
Mo1-E / 2.745 / 2.763 / 2.344 / 2.370 / 2.482 / 2.504 / 2.670 / 2.693
Mo2-E / 2.753 / 2.762 / 2.341 / 2.370 / 2.494 / 2.504 / 2.664 / 2.692
B1-B2 / 1.760 / 1.749 / 1.775 / 1.786 / 1.910 / 1.786 / 1.803 / 1.785
B2-B3 / 1.744 / 1.752 / 1.738 / 1.745 / 1.667 / 1.744 / 1.740 / 1.745
B3-B4 / 1.735 / 1.752 / 1.818 / 1.795 / 1.767 / 1.792 / 1.747 / 1.787
B4-B2 / 1.795 / 1.798 / 1.745 / 1.745 / 1.747 / 1.744 / 1.742 / 1.743

Table S2.DFT calculated (B3LYP/def-TZVP level) energies of the HOMO and LUMO (eV) and HOMO-LUMO gaps (E = ELUMO-EHOMO, eV) for the clusters [(CpM)2B5H9Fe(CO)3], 4a, 5a and 6a.

Compound / (CpMo)2B5H9Fe(CO)3 / 4a / 5a / 6a
HOMO / -5.80 / -5.57 / -5.57 / -5.54
LUMO / -1.87 / -2.00 / -2.10 / -2.26
ΔE / 3.93 / 3.57 / 3.47 / 3.28
Vertical IP / 6.99 / 6.77 / 6.75 / 6.72
Adiabatic IP / 6.75 / 6.61 / 6.61 / 6.58

Table S3.DFT calculated and experimental 11B and 1H NMR chemical shifts δ (ppm) and IR (cm-1) stretching values for [(CpM)2B5H9Fe(CO)3], and 4a-6a

Compound / [(CpMo)2B5H9FeCO)3] / 4a / 5a / 6a
11B NMR / Exp. / Cal. / Exp. / Cal. / Exp. / Cal. / Exp. / Cal.
B1 / 29.7 / 34.6 / 44.7 / 44.1 / 44.9 / 44.6 / 45.6 / 45.9
B2 / 90.4 / 102.8 / -5.3 / -0.13 / -4.9 / 1.1 / -4.0 / 2.9
B3 / 90.4 / 102.8 / 86.7 / 98.5 / 85.9 / 100.2 / 85.6 / 102.4
B4 / -0.4 / 7.3 / 86.7 / 98.5 / 85.9 / 100.2 / 85.6 / 102.4
B5 / 41.4 / 43.4 / - / - / - / - / - / -
1H NMR
B-Ht / 8.0, 3,9, 0.9 / 7.6, 3.9, 2.2 / 8.2, 4.7 1.3 / 7.5, 4.7, 2.0 / 8.2, 4.7, 1.3 / 7.6, 4.7, 2.0 / 8.2, 4.3 / 7.6. 4.8
Mo-H-B / -15.5, -13.1 / -14.1,
-12.4 / -14.4 / -13.7 / -15.3 / -13.9 / -15.8 / -14.1
IR-values
COt / 1994 / 2031 / 1950 / 2054 / 1962 / 2050 / 1971 / 2043
BHt / 2479, 2467 / 2565, 2604 / 2473, 2009 / 2559, 2615 / 2493, 2015 / 2602, 2558 / 2471 / 2555

Figure S1. Localized molecular orbital (LMO) representation: (a) Bonding interaction between Mo-Mo and (b) Antibonding interaction between Mo-Mo

Figure S2. Optimized structure of [(CpM)2B5H9Fe(CO)3],at B3LYP/def2-TZVP level of theory

(purple: molybdenum, green: boron, violet: iron, red: oxygen, grey: carbon, yellow: E=S, Se, Te)

Cartesian coordinates for the calculated structure of [(CpM)2B5H9Fe(CO)3],(in Å)

F 0.00044 1.52749 0.04114C -3.47169 -0.99221 1.1959

Mo -1.48598 -0.79405 -0.14691C -3.61022 0.18439 0.40986

Mo 1.48553 -0.79461 -0.14679C -3.62196 -0.18923 -0.95237

B -0.00025 0.20372 -1.70691C -3.46753 -1.60459 -1.01453

H -0.00022 0.76757 -2.76193C -3.39059 -2.09644 0.32467

H -1.03721 -0.566 -1.88469C 3.6218 -0.19184 -0.95362

H 1.03697 -0.56561 -1.88457C 3.6104 0.18422 0.4079

B 0.87452 0.28986 1.61871C 3.47122 -0.9909 1.19604

H 1.54412 0.70109 2.51166C 3.38948 -2.09669 0.3268

B -0.87459 0.29028 1.61858C 3.46664 -1.6072 -1.0133

H -1.54423 0.70182 2.51136H 3.68923 1.18773 0.78988

B -0.00043 -1.22846 1.5794H 3.41899 -1.02313 2.27069

H -0.00058 -1.92857 2.54846H 3.27818 -3.12702 0.62156

B -0.00043 -2.47691 0.28425H 3.45796 -2.20701 -1.90834

H -0.00093 -3.61095 0.65115H 3.72274 0.47462 -1.79395

H -0.98368 -2.43677 -0.60147H -3.41927 -1.02639 2.2705

H 0.98283 -2.43729 -0.6014H -3.68854 1.18725 0.79363

C 0.00245 2.69657 1.38649H -3.72284 0.47872 -1.79151

O 0.00369 3.47093 2.22698H -3.45914 -2.20285 -1.91061

C 1.35282 2.29351 -0.82131H -3.27949 -3.12732 0.61759

O 2.19926 2.83046 -1.37834

C -1.35319 2.29473 -0.81825

O -2.20038 2.83245 -1.37338

Figure S3. Optimized structure of 4a (4a: Cp analogue of 4) at B3LYP/ def2-TZVP level of theory

Cartesian coordinates for the calculated structure of 4a (in Å)

B -0.00036 -2.49481 0.48723O -2.23025 2.96734 -1.24446

B -0.00002 -1.21309 1.73207O 0.00218 3.37833 2.31638

B -0.89752 0.28407 1.70361O 2.2291 2.96653 -1.2483

B 0.89768 0.28397 1.70337S -0.00017 -0.01949 -1.71808

C -3.63204 0.21028 0.21308H 0.00003 -1.84639 2.747

C -3.51959 -0.29561 -1.10561H -1.54247 0.78137 2.56994

C -3.36752 -1.70261 -1.01452 H 1.54289 0.78082 2.56976

C -3.40974 -2.06281 0.37234H -0.00079 -3.61883 0.88359

C -3.57737 -0.87918 1.11916H -0.9707 -2.47968 -0.41389

C 3.63163 0.21002 0.21331H 0.97051 -2.48029 -0.41337

C 3.57685 -0.87938 1.11948H -3.62699 -0.80724 2.19222

C 3.40949 -2.06307 0.37273H -3.74786 1.24545 0.48624

C 3.36759 -1.70300 -1.01418H -3.53662 0.28604 -2.01239

C 3.51959 -0.29599 -1.10536H -3.27274 -2.38556 -1.84262

C -1.38029 2.39448 -0.73866H -3.3376 -3.06067 0.77205

C 0.00144 2.62965 1.45336 H 3.273 -2.38606 -1.84221

C 1.37981 2.39404 -0.74099H 3.33731 -3.06091 0.77247

Fe 0.00026 1.55232 0.04161H 3.62621 -0.80727 2.19254

Mo -1.46011 -0.81267 -0.02743H 3.53692 0.28557 -2.0122

Mo 1.45991 -0.81303 -0.02764H 3.74722 1.24522 0.48644

Figure S4. Optimized structure of 5a (5a: Cp analogue of 5) at B3LYP/def2-TZVP level of thoery

Cartesian coordinates for the calculated structure of 5a (in Å)

C 3.55869 -0.32275 -0.94739B -0.00225 -1.20135 1.83919

C 3.64279 0.19617 0.36743H -0.00437 -1.83392 2.85468

C 3.55382 -0.88309 1.28348B 0.89532 0.29462 1.80642

C 3.39699 -2.07432 0.54492H 1.53726 0.79003 2.67634

C 3.39259 -1.72838 -0.84563B -0.89684 0.29626 1.80458

C -3.56065 -0.31843 -0.9455H -1.53961 0.79276 2.67328

C -3.64295 0.19706 0.37081B -0.00201 -2.48589 0.59792

C -3.55357 -0.88466 1.28396H -3.30926 -3.06804 0.94762

C -3.39784 -2.07386 0.54215H -3.57634 -0.80467 2.35726

C -3.39479 -1.72441 -0.84753 H -3.75771 1.23387 0.63825

C 1.39156 2.40628 -0.60661H -3.60772 0.25594 -1.85572

C 0.00322 2.63849 1.57342H -3.31636 -2.41298 -1.67258

C -1.39099 2.40689 -0.60293H 3.30905 -3.06741 0.95317

O 2.25313 2.9786 -1.09427H 3.57823 -0.80044 2.35654

O 0.00434 3.38469 2.43864H 3.3129 -2.41901 -1.66883

O -2.25382 2.97979 -1.08764H 3.60453 0.24922 -1.85918

Fe 0.00107 1.56904 0.1593H 3.75787 1.23367 0.63199

Se 0.00113 -0.00341 -1.76853H 0.97384 -2.4783 -0.29901

Mo 1.47305 -0.81678 0.08735H -0.97535 -2.47585 -0.30213

Mo -1.47408 -0.81509 0.08502H -0.00362 -3.60847 0.99929

Figure S5. Optimized structure of 6a (6a: Cp analogue of 6) at B3LYP/def2-TZVP level of theory

Cartesian coordinates for the calculated structure of 6a(in Å)

B -0.89327 0.29753 1.91715O -2.28373 3.00386 -0.88411

B 0.89454 0.29828 1.91619O -0.00108 3.37702 2.59572

B 0.00134 -1.19868 1.9484O 2.28316 3.00415 -0.88365

B 0.00105 -2.48241 0.70747 Te -0.00086 0.03015 -1.86633

C -3.65755 0.16983 0.5488H -3.27318 -3.08844 1.13854

C -3.61169 -0.35487 -0.76476H -3.36991 -2.45328 -1.48404

C -3.42789 -1.75937 -0.66192H -3.51539 -0.81653 2.53933

C -3.38325 -2.09829 0.72853H -3.77245 1.20792 0.81129

C -3.52524 -0.90403 1.46655H -3.69917 0.21129 -1.67682

C 3.65759 0.17002 0.55129H 3.70073 0.21606 -1.67431

C 3.6128 -0.35195 -0.76345H 3.77198 1.20759 0.81605

C 3.42928 -1.75674 -0.6636H 3.51413 -0.82052 2.53965

C 3.38384 -2.09849 0.72611H 3.2734 -3.08948 1.13399

C 3.525 -0.9058 1.4667H 3.3722 -2.449 -1.48718

C -1.40463 2.42416 -0.43532H 0.98071 -2.47722 -0.1893

C -0.00076 2.63942 1.72308H -0.98036 -2.4785 -0.18708

C 1.40406 2.42438 -0.43496H 0.00207 -3.6049 1.1105

Fe -0.00031 1.5867 0.29985H 0.00251 -1.83438 2.9623

Mo -1.49101 -0.8262 0.20698H 1.5357 0.78504 2.79198

Mo 1.4917 -0.82535 0.20547H -1.53375 0.78409 2.79354

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