π-Bonding and the Lone Pair Effect in Multiple Bonds between Heavier Main Group Elements

Abstract

ContentsI. Introduction 3463 II. Multiple Bonding Models 3466 III. Lone Pair Character versus Multiple Bonding 3468 IV. Doubly Bonded Compounds 3469 A. Compounds of Formula RE)ER (E ) Group 13 Element) 3469 B. Compounds of Formula RE)E′R 2 (E ) Group 13, E′ ) Group 14 Element) 3470 C. Dianions of Formula [R 2 E)ER 2 ] 2-(E ) Group 13 Element) 3470 D. Monoanions of Formula [R 2 E)E′R 2 ] -(E ) Group 13; E′ ) Group 14 Element) 3472 E. Compounds of Formula R 2 E−E ¨′R 2 (E ) Group 13; E′ ) Group 15 Element) 3472 F. Compounds of Formula R 2 E−E′R and [R 2 E−E′] -(E ) Group 13, E′ ) Group 16 Element) 3475 G. Compounds of Formula R 2 E)ER 2 and [RE ¨)E ¨R] 2-(E ) Group 14 Element) 3477 H. Compounds of Formula R 2 E)E ¨′R (E ) Group 14, E′ ) Group 15 Element) 3481 I. Compounds of Formula [R 2 E)E′R 2 ] + (E ) Group 14; E′ ) Group 15 Element) 3484 J. Compounds of Formula R 2 E)E′: (E ) Group 14; E′ ) Group 16 Element) 3485 K. Compounds of Formula RE ¨)E ¨R (E or E′ ) N, P, As, Sb, or Bi) 3486 L. Compounds of Formula RE)E′ (E ) Group 15, E′ ) Group 16 Element) 3489 V. Compounds with Formal Bond Order >2 and Triply Bonded Compounds 3490 A. Range of Compounds 3490 B. Compounds with Potential Triple Bonding to a Group 13 Element 3491 C. Compounds with Potential Triple Bonding to a Group 14 Element 3493 D. Compounds with Triple Bonding between Group 14 and 15 Elements 3494 E. Compounds with Triple Bonding between Group 15 Elements 3495 VI. Conclusions 3495 VII. Acknowledgments 3496 VIII. References 3496Philip Power received his B.A. degree from Trinity College Dublin in 1974 and his D.Phil. degree, under the supervision of M. F. Lappert, from the University of Sussex in 1977. After postdoctoral studies with R. H. Holm at Stanford, he joined the faculty at the University of California, Davis, where he is currently Professor of Chemistry. His main research interests involve the structural chemistry of organoalkali metal and organocopper compounds, low-coordinate transition metal chemistry, multiple bonding in main group chemistry, and the development of new ligands for the stabilization of low coordination numbers, unusual oxidation states, and multiple bonding in both transition metal and heavier main group compounds. He is a recipient of fellowships from the A. P. Sloan and Alexander von Humboldt foundations. In addition he has been Reilly Lecturer at the University of Notre Dame (1995), Faculty Research Lecturer at the University of Iowa (1993), and the

[Pb2I3(18‐crown‐6)2][SnI5] and CdI2(18‐crown‐6)·2I2: Two Layered Iodine Networks with Crown‐ether Coordinated Pb2+ and Cd2+

“…. This finding is in accordance with the increased radius as well as with a less pronounced lone-pair effect [25,26]. All C-O and C-C bond lengths of 18-crown-6 match with literature data [27].…”

Terminal, Anionic Carbide, Nitride, and Phosphide Transition‐Metal Complexes as Synthetic Entries to Low‐Coordinate Phosphorus Derivatives

“…Consideration of the ELF has been exceptionally enlightening with regard to bonding patterns in main-group systems, [86] and is equally informative in the present case of the complexed PPMe 2 model ligand. Multiple bonds between heavier main-group elements is an area of current intense interest to experimentalists and theoreticians alike, [87,88] and it is an area to which the methods proposed herein may contribute generously.…”

Synthesis and Structures of a Series of Bulky “Rind-Br” Based on a Rigid Fused-Ring s-Hydrindacene Skeleton

“…To improve the selectivity of REind-Br, we examined various bromination conditions. For example, the bromination of EP 5 ind-H and EHind-H with gentle warming to about 35°C using a large excess amount of Br 2 (ca. 20 equiv) led to a somewhat better selectivity to generate P products, EP 5 ind-Br and EHind-Br, could not be suppressed even under these conditions.…”

“…For example, the bromination of EP 5 ind-H and EHind-H with gentle warming to about 35°C using a large excess amount of Br 2 (ca. 20 equiv) led to a somewhat better selectivity to generate P products, EP 5 ind-Br and EHind-Br, could not be suppressed even under these conditions. However, the major products, PEind-Br, BEind-Br, P 5 Eind-Br, and HEind-Br, could be isolated as colorless crystals by recrystallization from hexane or hexane/EtOH in 1021% overall yields for the 4 steps.…”