Actinide Metal Atom (Th and U) Reactions to Form Novel Molecules

Actinide Metal Atom (Th and U) Reactions to Form Novel Molecules

Metal-Carbon Multiple BondsActinide Metal Hydrides

Lester Andrews, Chemistry Department, University of Virginia, Charlottesville, Virginia

Also Jon Lyon, Han-Gook Cho, Xuefeng Wang,Bjorn Roos, Han-shi Hu, Jun Li, Colin Marsden,

Laura Gagliardi

Apparatus for Laser Ablation and Matrix Isolation

7 Ko r 4 K

1 0 6 4 n m

M e ta lTa rg e t

A r / C H C H X N e /C H o r C H X

4 3

4 3

o ru v, v is

CsI window for IR

YAG laser ablation of Zr

9.17.00 1:37 PM8 3.3 Periodic Table

Reading the Periodic Table: ClassificationReading the Periodic Table: ClassificationNonmetals, Metals, Metalloids, Noble gases

Novel Organometallic Molecules

M + CH4 CH3—MH ↔ CH2=MH2 ↔ HC≡MH3

M + CH3X CH3—MX ↔ CH2=MHX ↔ HC≡MH2X

M + CH2X2 CH2X—MX CH2=MX2 HC≡MHX2

M + CHX3 CHX2—MX CHX=MX2 HC≡MX3

M + CX4 CX3—MX CX2=MX2 XC≡MX3

B3LYP density functional calculated structures for methylidene molecules

C C C C C

CC

Y Zr Nb Mo Ru

ThU

C Tc

Infrared spectra of the Th + CH4 reaction productJ. Phys. Chem. A 2005, 105, 6796.

Dep at 7 K

240-380 nm

> 220 nm

Anneal 26 K

> 420 nm

Observed and Calculated (B3LYP/6-311++G(3df,3pd)/SDD) Frequencies for CH2=ThH2

ApproximateModeDescription

CH2=ThH213CH2=ThH2 CD2=ThD2

Obs. Calc. Int. Obs. Calc. Int. Obs. Calc. Int.

CH2 stretch 3142.6 2 3132.2 2 2321.7 2

CH2 stretch 2861.4 11 2854.9 11 2084.7 2

ThH2 stretch 1435.7 1434.9 350 1435.7 1434.8 350 b 1023.5 110

ThH2 stretch 1397.1 1394.2 698 1391.7 1394.2 698 b 1005.7 98

CH2 bend 1327.5 11 1320.5 11 989.0 340

C=Th stretch 670.8 679.6 178 651.5 659.7 173 602.9 614.8 127

CH2 wag 634.6 633.0 161 629.2 627.5 157 499.2 495.1 109

ThH2 bend 458.7 492.8 110 492.3 108 355.8 34

ThH2 rock 460.8 5 458.2 4 344.4 29

CH2 twist 343.0 30 342.5 30 245.3 18

ThH2 wag 321.9 65 321.6 66 230.2 30

CH2 rock 248.4 62 248.1 62 177.5 30

CH2=ThH2, CH2=ThHF, CH2=UH2, CH2=UHF

1 4 8 0 1 3 8 01 4 3 0

W a v e n u m b e rs (c m )-1

0 .0 0

0 .1 6

0 .3 2

Abs

orba

nce

T h + C H 4

U + C H 4

U + C H F3

T h + C H F3

(a )

(b )

(c )

(d )

C H F3

C H F3

CH2=UHF

CH2=ThHF

Structures calculated with different theoretical methodsInorg. Chem. 2007, 46, 4917.

BPW91/PW91/CASPT2

One singly-occupied U 5f orbital in CH2=UH2

Reactions of laser-ablated U atoms with CH2XY (XY = F2, FCl, and Cl2) lead to a series of new actinide methylidene complexes CH2=UF2,

CH2=UFCl, and CH2=UCl2, which have agostic structures stabilized by interaction through the open-shell U 6d-5f orbitals.

Angew. Chem. Intl. Ed. 2007, 46, 9045.

Structures for Th, U and NH3 Reaction ProductsChem. Eur. J. 2007, 13, 5601.

B3LYP/CCSD

1 .90 31 .01 5

17 3 .3 o2 .04 9

2 .04 110 1 .6 o

10 0 .7 o

2 .19 3

2 .07 3

1 .01 8

1 .01 7

10 7 .6 o

12 9 .8 o

1 2 2 .6 o

10 4 .0 o

2 .1 7 6(2 .1 9 6 )

2 .0 3 7(2 .0 5 4 )1 2 7 .1

(1 2 6 .8 )

11 7 .9(11 8 .0 )

1 3 3 .7(1 3 4 .0 )

1 .0 2 3(1 .0 2 2 )

1 .0 1 4(1 .0 1 3 )

2 .1 0 3 (2 .1 0 9 )

1 .9 5 1 (1 .9 6 6 ) 1 .0 1 4

(1 .0 1 3 )

1 7 2 .9 (1 7 3 .0 )

1 0 2 .4 (1 0 2 .0 )

1 0 0 .6 (1 0 3 .2 )

H-N=ThH2 H-N=UH2

1.9031.951

62.1% d

30.1% fHOMO

46.2% d

48.5% fHOMO

CH2=ThH2

2.103

CH2=UH2

2.045

Small amount of triple bond character

Novel Organometallic Molecules

M + CH4 CH3—MH ↔ CH2=MH2 ↔ HC≡MH3

M + CH3X CH3—MX ↔ CH2=MHX ↔ HC≡MH2X

M + CH2X2 CH2X—MX CH2=MX2 HC≡MHX2

M + CHX3 CHX2—MX CHX=MX2 HC≡MX3

M + CX4 CX3—MX CX2=MX2 XC≡MX3

Th atom reactions with CHF3, CHF2Cl, CHFCl2, and CHCl3

5 8 0 4 8 0W a v e n u m b e rs (c m )

-1

0 .0 0

0 .4 5

Abs

orba

nce

( a )

(b )

(c )

(d )

CHF3

Approximate HC÷ThF3 DC÷ThF3

Mode Obs.(argon matrix) B3LYP Calc. (int.) Obs.(argon matrix) B3LYP Calc. (int.)

C-H stretch, a1 3108.6 (5) 2288.6 (0)

Th-F stretch, a1 565.4 568.5 (17) 563.4 566.0 (30)

Th-F stretch, e 521.3 526.0 (419) 520.6 525.7 (404)

C-Th stretch, a1 502.1 508.9 (180) 493.1 492.3 (160)

H-C-Th bend, e 425.9 (68) 328.3 (56)

F-Th-F bend, a1 120.5 (1) 117.4 (4)

F-Th-F bend, e 117.5 (27) 115.4 (27)

C-Th-F bend, e 106.0 (37) 102.0 (17)

Observed and Calculated Fundamental Frequencies for HC÷ThF3 in C3v

Symmetry in the Triplet Ground Electronic StateEur. J. Inorg. Chem. 2008, in press.

Energies of Th and U atom reactions with CHF3 and CF4

• 2.48 Å 2.16 Å 2.41 Å 2.13 Å 1.94 Å

CHF2--ThF CHF=ThF2 HC—ThF3 CHF=UF2 HC≡UF3

+76 kcal/mol + 46 kcal/mol 0 kcal/mol + 23 kcal/mol 0 kcal/mol

2.26 Å 2.47 Å 2.40 Å

CF2=ThF2 CF2—ThF2 FC—ThF3

+ 51 kcal/mol + 51 kcal/mol 0 kcal/mol

2.45 Å 2.40 Å 2.01 Å

CF2—UF2 CF2=UF2 FC≡UF3

+ 21 kcal/mol + 20 kcal/mol 0 kcal/mol

C

Th

H 1.0932 .36 8

2.085

109.

4

109.5

C

Th

Cl

Cl Cl

1.0922 .36 2

2.594

107.

1

111.7

C

Th

F

F F

1.0922 .41 2

2.123

108.

2

110.7

C

Th

F

F F

F 1.3002 .39 7

2.120

109.

5

109.4

C

Th

Cl

Cl Cl

Cl1.6592 .35 4

2.592

107.

9

110.9

C

Th

Cl

Cl

1.2942 .36 9

2.604

109.

0

110.1

C

ThCl

Cl1.6672 .38 6

2.621

110.4

H

H H

H H

F

FF

F

2.096

109.1

109.8

109.

1 109.0

108.8

2.108

C

Th

Cl

Cl1.092

2 .37 9

2.608

108.

0

112.1

C

ThCl

1.0922 .39 5

2.623

111.3FF

F

2.100

107.2

111.1

107.

6 108.1

110.9

2.109

HH

B3LYP Structures for HC-ThX3 and XC-ThX3 Complexes

N a tu ra l C h arg es

0 .1 0

-0 .8 4

3 .11-0 .7 9 (x 3 )

S p in D en s itie s

-0 .0 7

1 .8 7

0 .1 7 0 .0 1 (x 3 )

Uranium atom reaction productsProc. Natl. Acad. Sci. 2007, 104, 18919.

0 .9 0

0 .0 0

Abs

orba

nce

5 8 0W a v e n u m b e rs (c m )

-1 5 0 0(a )(b )(c )

(d )(e )( f)

(g )(h )( i)

P

P

U F 5 U F 3

U+CDF3

U+CF4

U + CDF3

U + CF4

U + CDF3

U + CHF3

Observed and calculated (PW91/TZ2P) fundamental vibrational

frequencies for the C3v F3U≡CX (X = H, D, F) molecules

• Mode description F3U≡CH

F3U≡13CH F3U≡CD F3U≡CF

Obs. Calc. Obs. Calc. Obs. Calc. Obs. Calc.

C-X str, a1 2979(0.1) 2969(0.2) – 2200(1.5) – 1268(312)

U≡CX str, a1 – 747(46) -- 721(42) – 717(41) – 441(34)

U-F sym str, a1 576.2 585(122) -- 585(123) 576.2 586(123) 578.7 589(118)

U-F antisym str, e 540.2 561(284) 539.2 559(280) 535.9 541(207) 536.4 544(177)

U≡C-X bend, e 527.5 508(34) -- 506(24) -- 412(49) – 311(28)

Calculated structures of (a) F3U≡CH, (b) Cl3U≡CH, (d) Br3U≡CH, and (d) F3U≡CF

Comparison of the molecular orbitals of ethyne HC≡CH and the uranium-methylidyne F3U≡CH and F3U≡CF complexes (isosurface =0.05 atomic unit)

HC≡CH F3U≡CH F3U≡CF

π1-MO

π2-MO

σ-MO

Uranium atom reaction productsA

bsor

banc

e

1 .0

0 .05 4 0 4 2 0

W a v e n u m b e rs (c m )-1

(a )(b )(c )(d )

(e )( f)

(g )(h )

( i)( j)(k )( l)

C H B r 3

CHCl3

13CHCl3

CDCl3

CHBr3

Observed and calculated (PW91/TZ2P) fundamental vibrational

frequencies for the C3v X3U≡CH (X = Cl, Br) molecules

•Mode description Cl3U≡CH Cl3U≡13CH Cl3U≡CD Br3U≡CH

Obs.b Calc. Obs. Calc. Obs. Calc. Obs. Calc.

C-H str, a1 3001(2) 2991(2) 2219(7) 3005(3)

U≡CX str, a1 –c 770(69) –c 744(65) –c 738(64) –c 777(70)

U≡C-H bend, e 527.2 522(224) 522.8 518(218) 415.9 410(216) 527.6 527(178)

U-X sym str, a1 339(29) 339(29) 339(29) 225(84)d

U-X antisym str, e 329(140) – 329(140) – 326(100) 216(10)d

Carbon-Uranium Triple Bonds

•

• 1.764 Å 1.808 Å 1.910 Å

• C≡U≡O HC≡UCl3

• PW91 bond lengths • Zhou, Andrews, Li, Bursten, Lyon, Hu, Andrews, Li,• J. Am. Chem. Soc. 1999, 121, 9712. Proc. Natl. Acad. Sci. U.S.• Earlier work: 2007, 104(48), 18919.• Tague, Andrews, Hunt,• J. Phys. Chem. 1993, 97, 10920. • Pyykko, Li, Runeberg,

• J. Phys. Chem. 1994, 98, 4809.

Reactions of Mo atoms with CHX3 molecules:

HC≡MoX3

Reactions of Mo atoms with CHX3 moleculesOrganometallics, 2007, 26, 6373.

9 7 0

(a )

(b )

(c )

(d )

9 9 5W a v e n u m b e rs (c m )

-1

0 .0 0

0 .0 4

Abs

orba

nce

9 2 9 8

1 0 0

CHF3

CHF2Cl

CHFCl2

CHCl3

Natural Mo isotopic splittings

ApproximateDescription

HC≡MoCl3 DC≡MoCl3 HC≡MoF3

obs calc int obs calc int obs calc int

C-H str, a1 3058.2 3212.2 35 2296.2 2387.9 24 3073.1 3221.2 39

HC≡Mo str, a1 978.1b 1051.9 8 932.4b 1005.8 6 986.0c 1065.0 20

Mo-X str, e 438.7 425.0 81x2 436.4 423.0 74x2 689.2 683.4 210x2

Mo-X str, a1 380.8 9 380.7 9 664.6 651.7 60

H-C-Mo def, e 658.9 660.2 76x2 533.4 533.6 52x2 645.4 642.7 30x2

C-Mo-X def, e 237.7 7x2 212.3 7x2 288.7 5x2

Mo-X3 umb, a1 144.0 0 143.7 0 228.0 9

Mo-X2 bend, e 100.4 0 100.4 0 163.6 8x2

Observed and Calculated [B3LYP/6-311++G(2d,p) ] Fundamental Frequencies of HC≡MoX3 Complexes in the Ground 1A1 Electronic State with the C3v Structure

Span the periodic table

U + H2

U in solid para-hydrogen at 4 KJ. Phys. Chem. A, 2007, 111, 6383.

1 5 0 0 1 4 0 0 1 3 0 0 1 2 0 0 11 0 0 1 0 0 0

0 .0 0

0 .0 5

0 .1 0

Abs

orba

nce

W av en u m b ers (c m )-1

(a )

(b )

(c )

(d )

d ep o sitio n

irrad ia tio n (> 5 3 0 n m )

irrad ia tio n (> 4 7 0 n m )

an n e a lin g to 7 K

U + -Hp 2

U H (H )4 2 x

U H (H )2 2 x

(H ) U H2 x 2 2

p -H 2

U H 4 U H 2

Th in solid H2, HD, and D2 at 4 KJ. Phys. Chem. A, 2008, in press.

1500 1400 1300 1200 1100 1000 9000.00

0.20

0.40

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

Wavenumbers (cm )-1

Abs

orba

nce

ThH (H )4 2 x

ThD (D )4 2 x

ThD4

ThD2

ThH4

ThH2

(i)

(j)

(k)

CH4

Ground state total CASSCF electron density

WH4 (triplet) ThH4(singlet) UH4(triplet)

WH44H2 (singlet) ThH44H2(singlet) UH46H2(triplet)

Ball Game!!!

• We have investigated reactions of the laser-ablated actinide metal atoms Th and U with small molecules, and assigned the new reaction products from matrix infrared spectra and comparison with DFT calculated isotopic frequencies. These new molecules are important for their unique bonding and structure and their unusual chemistry.

• We thank NSF for support and you for your kind attention.

Matrix-Isolation

Spectroscopy

Synthesis

Gas-Phase Theory

PERSPECTIVE