Table 1 The ΔM‒A‒X angle, QTAIM atomic charges of M and A in MAX3 systems, Q(M) and Q(A), the IQA interaction energy and its interatomic exchange-correlation and Coulombic energy components between metal and Al, B, or central C atoms in the studied systems, VInt(M,A), VXC(M, A) and VC(M, A), and those of the metals with the substituents on the central atom, VXC(M, X) and VC(M, X), in kcal.mol−1.

From: Collective interactions among organometallics are exotic bonds hidden on lab shelves

Molecules

ΔM‒A‒X

Q(M)

Q(A)

Q(X)

VXC(M,A)

VXC(M,X)

VC(M,A)

VC(M,X)

VInt(M,A)

VInt(M,X)

LiBH3−a

5.11

−0.010

1.326

−0.772

−20.8

−4.9

42.1

−27.8

21.3

−32.7

NaBH3−a

4.59

−0.195

1.524

−0.776

−18.7

−6.6

19.3

−9.5

0.6

−16.1

KBH3−a

3.11

−0.238

1.585

−0.781

−13.7

−6.0

13.8

−6.3

0.1

−12.3

MgBH3

3.36

0.468

1.627

−0.698

−33.6

−11.9

133.9

−58.2

100.3

−70.1

CaBH3a

0.91

0.613

1.572

−0.729

−24.5

−11.1

163.7

−76.9

139.2

−88.0

LiAlH3

16.27

0.206

1.241

−0.816

−48.1

−2.8

23.6

−27.0

−24.5

−29.8

NaAlH3−a

14.86

−0.135

1.587

−0.817

−39.1

−3.4

3.5

−2.1

−35.6

−5.5

KAlH3−a

13.13

−0.204

1.681

−0.825

−24.1

−2.7

−0.9

0.4

−25.0

−2.3

MgAlH3

2.83

0.172

2.112

−0.761

−17.9

−7.3

41.9

−13.7

23.9

−21.0

CaAlH3

3.73

0.352

1.986

−0.779

−24.9

−6.5

80.2

−30.2

55.3

−36.7

i−CaAlH3a,b,d

−33.89

0.887

1.471

−0.786

−11.3

−24.1

239.5

−128.9

228.3

−153.0

LiCF3

25.14

0.918

1.197

−0.705

−21.3

−0.7

93.8

−78.9

72.5

−79.6

NaCF3

25.29

0.865

1.261

−0.709

−27.8

−1.1

98.8

−67.7

71.0

−68.8

BeCF3+

19.12

1.625

1.303

−0.642

−61.6

−3.4

157.8

−151.3

96.2

−154.7

MgCF3+c

19.78

1.453

1.512

−0.655

−62.9

−4.5

227.0

−120.4

164.1

−124.9

i-LiCF3b,c,d

−31.33

0.932

1.203

−0.712

−0.6

−9.1

223.2

−122.8

222.6

−132.0

i-NaCF3b,c,d

−30.18

0.934

1.220

−0.718

−0.9

−10.1

188.8

−103.8

187.9

−113.9

i-KCF3b,d

−29.67c

0.942

1.215

−0.719

−0.9

−11.6

168.0

−93.1

167.1

−104.7

i-MgCF3+b,d

−33.31

1.830

1.229

−0.686

−2.3

−19.2

403.1

−234.2

400.8

−253.4

i-CaCF3+b,d

−32.12

1.812

1.219

−0.677

−2.1

−24.5

351.1

−194.7

349.0

−219.1

i-SrCF3+b,d

−31.72

1.838

1.221

−0.686

−1.8

−23.6

338.3

−188.6

336.5

−212.2

i-MgC(CN)3+b

−26.32

1.776

0.243

−0.340

−3.3

−19.5

67.1

−122.5

63.8

−142.0

i-CaC(CN)3+b

−19.53

1.727

0.184

−0.304

−7.2

−23.5

41.5

−80.0

34.3

−103.5

i-SrC(CN)3+b

−17.83

1.756

0.172

−0.309

−7.2

−22.3

37.1

−75.1

29.9

−97.4

LiCH3

22.64

0.899

−0.609

−0.097

−25.2

−0.5

−141.8

−7.9

−167.0

−8.4

NaCH3

20.98

0.757

−0.536

−0.074

−40.1

−1.1

−86.3

−4.3

−126.4

−5.4

KCH3

22.09

0.805

−0.516

−0.096

−35.3

−1.0

−77.8

−6.2

−113.1

−7.2

BeCH3+

19.08

1.669

−0.971

0.101

−68.5

−1.5

−476.9

30.8

−545.4

29.3

MgCH3+

16.63

1.397

−0.605

0.069

−78.9

−1.9

−196.6

16.4

−275.5

14.5

CaCH3+

22.07

1.618

−0.621

0.001

−71.1

−1.9

−201.3

4.0

−272.4

2.1

SrCH3+

22.03

1.616

−0.587

−0.010

−71.9

−1.9

−183.5

1.9

−255.4

0.0

LiC(Ph)3

−6.73

0.894

−0.218

−0.225

−10.7

−5.5

−49.6

−31.0

−60.3

−36.5

NaC(Ph)3

−5.35

0.907

−0.161

−0.249

−8.8

−6.8

−29.0

−29.4

−37.8

−36.2

KC(Ph)3

−3.84

0.894

−0.142

−0.250

−10.8

−10.1

−22.7

−25.2

−33.5

−35.3

MgC(Ph)3+

10.67

1.088

−0.391

0.101

−56.3

−10.0

−120.9

7.6

−177.2

−2.4

CaC(Ph)3+

−6.42

1.554

−0.214

−0.113

−29.8

−26.0

−65.4

−47.4

−95.2

−73.4

SrC(Ph)3+

−4.37

1.561

−0.214

−0.116

−32.8

−25.8

−64.5

−41.9

−97.3

−67.7

LiC(CH3)3c

21.40

0.882

−0.470

−0.137

−24.8

−0.9

−125.9

−9.2

−150.7

−10.1

NaC(CH3)3c

20.60

0.716

−0.329

−0.129

−38.8

−2.0

−65.8

−6.7

−104.6

−8.7

KC(CH3)3c

21.18

0.799

−0.295

−0.168

−32.2

−1.6

−58.8

−10.2

−91.0

−11.8

BeC(CH3)3+

16.88

1.417

−0.772

0.119

−79.2

−3.8

−357.6

27.2

−436.8

23.4

MgC(CH3)3+

15.52

1.136

−0.428

0.097

−72.1

−5.0

−130.2

15.2

−202.3

10.2

CaC(CH3)3+

19.04

1.539

−0.412

−0.043

−71.5

−3.7

−153.6

−5.6

−225.3

−9.3

i-LiC(CH3)3d

−12.92

0.799

−0.197

−0.201

−14.1

−11.6

−27.1

−32.3

41.2

−43.9

i-NaC(CH3)3b,d

−11.21

0.754

−0.125

−0.210

−9.3

−12.8

−9.6

−26.1

−18.9

−38.9

i-KC(CH3)3b,d

−7.01

0.783

−0.162

−0.207

−13.7

−14.2

−16.4

−21.7

−30.1

−36.0

i-BeC(CH3)3+c,d

−16.98

1.520

−0.274

−0.082

−25.5

−31.0

−130.6

−81.3

−156.1

−112.3

i-MgC(CH3)3+b,d

−5.76

0.300

0.033

0.222

−7.1

−10.9

1.1

4.9

−6.1

−6.0

i-CaC(CH3)3+c,d

−3.55

1.460

−0.230

−0.077

−45.8

−24.9

−68.2

−25.1

−114

−50.0

i-SrC(CH3)3+e,d

−0.32

1.466

−0.247

−0.073

−53.1

−23.0

−74.3

−20.2

−127.4

−43.2

  1. The prefix i- denotes structures with an inverted geometry that have a negative M‒A‒X angle. The ΔM‒A‒X angle is defined as the difference between M‒A‒X angle and a right angle as defined in ref. 9.
  2. aData obtained from BS-DFT calculations.
  3. bThe metal forms multiple (3,-1) CPs with the AX3 fragment.
  4. cThe global minimum of the molecule.
  5. di- represents inverted structures, see Fig. 1.
  6. eThe global minimum of the molecule has a CS point group, 1.6 kcal.mol−1 lower in energy; therefore, it is not discussed here.