Abstract
The nature of the bonding between lithium atoms, in low-spin and maximum-spin Li n (n=2–6) clusters, was investigated using the topological electron localization function (ELF) approach. The maximum-spin clusters are especially intriguing since their bonding is sustained without having even a single electron pair! Hence this type of bonding had been called “no-pair ferromagnetic-bonding” [Danovich, Wu, Shaik J Am Chem Soc 121:3165 (1999); Glokhovtsev, Schleyer Isr J Chem 33: 455 (1993); de Visser, Danovich, Wu, Shaik J Phys Chem A 106:4961 (2002)]. The following conclusions were reached in the study: (a) In the ground state of Li n , covalent bonding between Li atoms is accounted by the presence of the disynaptic valence basins, which exhibit a significant degree of inter-basin delocalization. (b) Except for the 3Li2 case, the valence basins of all maximum-spin clusters are populated by unpaired electrons. The valence basins are located off Li–Li axis (or Li–Li–Li plane), so that their spatial distribution minimizes the mutual Pauli repulsion and screens the electrostatic repulsion between the Li cores. The inter-basin delocalization is rather high, thereby indicating that the unpaired electrons are virtually delocalized over all the valence basins. (c) The ELF analysis shows that Li atoms in the low-spin clusters are bonded by “two-center two-electron” and “three-center two-electron” bonds. (d) In the maximum-spin species, bonding is sustained by “two-center one-electron” and “three-center one-electron” bonds. The latter picture is complementary to the valence bond picture [Danovich, Wu, Shaik J Am Chem Soc 121 3165 (1999); de Visser, Danovich, Wu, Shaik J Phys Chem A 106: 4961 (2002)], in which the bicentric ferromagnetic-bonding is delocalized over all the short Li–Li contacts, by the mixing of the ionic structures and other nonredundant structures into the repulsive high-spin covalent structure in which all the electrons populate the 2s atomic orbitals, i.e., the 2s 1 a 2s 1 b 2s 1 i ... 2s 1 n configuration. In such a manner bonding can be sustained from “purely ferromagnetic interactions” without electron pairing.
Similar content being viewed by others
References
Danovich D, Wu W, Shaik S (1999). J Am Chem Soc 121:3165
Glokhovtsev MN, Schleyer PVR (1993). Isr J Chem 33:455
deVisser SP, Danovich D, Wu W, Shaik S (2002). J Phys Chem A 106:4961
Higgins J, Callegari C, Reho J, Stienkemeier F, Ernst WE, Lehmann KK, Gutowski M, Scoles G (1996). Science 273:629
Higgins J, Ernst WE, Callegari C, Reho J, Lehmann KK, Scoles G (1996). Phys Rev Lett 77:4532
Higgins J, Callegari C, Reho J, Stienkemeier F, Ernst WE, Gutowski M, Scoles G (1998). J Phys Chem A 102:4952
Fiortti A, Comparat D, Crubelier A, Dulieu D, Mansou-Seeuws F, Pillet P (1998). Phys Rev Lett 80:4402
Higgins J, Hollebeek T, Reho J, Ho T-S, Lehmann KK, Rabitz H, Scoles G, Gutowski M (2000). J Chem Phys 112:5751
Reho JH, Higgins J, Nooijen M, Lehmann KK, Scoles G (2001). J Chem Phys 115:10265
Brühl FR, Miron RA, Ernst WE (2001). J Chem Phys 115:10275
Bader RFW (1994). Atoms in molecules: a quantum theory. Oxford University Press, Oxford
Silvi B, Savin A (1994). Nature 371:683
Becke AD, Edgecombe KE (1990). J Chem Phys 92:5397
Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR, Montgomery, Jr. JA, Vreven T, Kudin KN, Burant JC, Millam JM, Iyengar SS, Tomasi J, Barone V, Mennucci B, Cossi M, Scalmani G, Rega N, Petersson GA, 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 JE, Hratchian HP, Cross JB, Adamo C, Jaramillo J, Gomperts R, Stratmann RE, Yazyev O, Austin AJ, Cammi R, Pomelli C, Ochterski JW, Ayala PY, Morokuma K, Voth GA, Salvador P, Dannenberg JJ, Zakrzewski VG, Dapprich S, Daniels AD, Strain MC, Farkas O, Malick DK, Rabuck AD, Raghavachari K, Foresman JB, Ortiz JV, Cui Q, Baboul. AG, Clifford S, Cioslowski J, Stefanov BB, Liu G, Liashenko A, Piskorz P, Komaromi I, Martin RL, Fox DJ, Keith T, Al-Laham MA, Peng CY, Nanayakkara A, Challacombe M, Gill PMW, Johnson B, Chen W, Wong MW, Gonzalez C, Pople JA (2003). Gaussian 2003, Revision B.02. Gaussian, Inc., Pittsburgh PA
Becke AD (1993). J Chem Phys 98:5648
Perdew JP, Wang Y (1992). Phys Rev B 45:13244
Krishnan R, Binkley JS, Seeger R, Pople JA (1980). J Chem Phys 72:650
Clark T, Chandrasekhar J, Spitznagel GW, Schleyer PVR (1983). J Comp Chem 4:294
Frisch MJ, Pople JA, Binkley JS (1984). J Chem Phys 80:3265
Jones RO, Lichtenstein AI, Hutter J (1997). J Chem Phys 106:4566
Wheeler SE, Sattelmeyer KW, Schleyer PVR, Schaefer III HF (2004). J Chem Phys 120:4683
de Visser SP, Alpert Y, Danovich D, Shaik S (2000). J Phys Chem A 104:11223
Noury S, Krokidis X, Fuster F, Silvi B (1997). TopMoD package
Kohout M, Savin A (1996). Int J Quant Chem 60:875
Silvi B (2004). Phys Chem Chem Phys 6:656
Silvi B (2003). J Phys Chem A 107:3081
Noury S, Colonna F, Silvi B (1998). J Mol Struct 450:59
McWeeny R (1992). Methods of molecular quantum mechanics. Academic, London
Bader RFW (1975). In: Chalvet O, Daudel R, Diner S, Malrieu JP (eds). Localization and delocalization in quantum chemistry, vol I. Reidel, Dordrecht, pp 15–38
Savin A, Silvi B, Colonna F (1996). Can J Chem 74:1088
Krokidis X, Silvi B, Alikhani ME (1998). Chem Phys Lett 292:35
Berski S, Andrés J, Silvi B, Domingo LR (2003). J Phys Chem A 107:6014
del CarmenMichelini M, Sicilia E, Russo N, Alikhani ME, Silvi B (2003). J Phys Chem A 107:4862
Pilme J, Silvi B, Alikhani ME (2003). J Phys Chem A 107:4506
Rousseau R, Marx D (2000). Chem Eur J 16:2982
McAdon MH, Goddard III WA (1988). J Phys Chem 92:1352
Shaik SS, Hiberty PC (1985). J Am Chem Soc 107:3089
Maynau D, Malrieu J-P (1988). J Chem Phys 88:3163
Author information
Authors and Affiliations
Corresponding author
Additional information
Dedicated to Jean-Paul Malrieu, a friend and a poet-scientist
Rights and permissions
About this article
Cite this article
Alikhani, M.E., Shaik, S. A Topological Study of the Ferromagnetic “No-Pair Bonding” in Maximum-Spin Lithium clusters: n+1Li n (n=2–6). Theor Chem Acc 116, 390–397 (2006). https://doi.org/10.1007/s00214-006-0081-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00214-006-0081-9