Transition metal complexes of the naked pnictide elements

Abstract

Even though transition metal compounds containing "naked" pnictide elements (E) have been known for many decades now, the chemistry of this interesting class of compound continues to provide surprises and intellectual challenges in describing new structures and interesting bonding patterns. The number of ligand sets that now support naked pnictide ligands has expanded from the traditional organometallic ligand sets to include metal alkoxides and N-heterocyclic carbene species, and complexes are known from the early transition metals to the end of the d-block. In this review, complexes are presented based on their structural similarities starting with metal-rich compounds containing isolated E atoms in a variety of coordination environments presented in order of increasing metal connectivity. Subsequently, compounds possessing Ex fragments with x ranging from 2 to 24 are presented in increasing nuclearity. Finally, structures with low ligand ratios and metal to pnictide ratios close to one are discussed, followed by compounds that have no supporting ligands and resemble metal allow fragments. Where appropriate, electron counting rules have been employed to explain observed structures and reactivity patterns. A particularly intense area of study has been the creation of inorganic-organometallic-organic polymers and frameworks based on discrete clusters with Ex fragments (2 £ x £ 6) where the Ex fragment provides a node for structure growth in combination with transition metal coordination frameworks based on Cu and Ag and suitable organic ligands. Simple oligomers, 1-dimensional polymers, 2-dimensional polymeric networks and 3-dimensional polymeric structure have all be prepared and structurally characterized. In addition to the structural data, synthetic methods are described. The review encompasses 170 references, 118 figures and nine schemes.

Cyclic Tribismuthide as a Piano Stool Complex Ligand – Synthesis and Crystal Structure of (η3‐Bi3)M(CO)33– (M = Cr, Mo)

“…Supporting Information (see footnote on the first page of this article): Details regarding the X‐ray diffraction experiments as well as additional information concerning the theoretical calculations for the Cr species described in the article. A review by K. H. Whitmire concerning transition metal complexes of the naked pnictide elements will be published in December 2018 …”

Coordinated “Naked” Pnicogenes and Catalysis

“…Here we discuss the chemistry of mixed, transition metal/main group element compounds, prevalently from the viewpoint of the transition metal chemistry, and catalysis [23], but this approach is carrier of useful information for main group chemistry too [24][25][26][27][28]. [19,20]; Schematic view of the structure (B) of complex 5 [21].…”

“…The X-ray diffraction structure of complex 28 was determined (Figure 17). It is interesting that the two bulky M(CO)5 groups do not significantly alter the structure of the "ligand" fragment in complex 28, but the P2 unit undergoes additional activation, as indicated by the length of the P-P bond: P2 in gas phase 189.3 pm [74], in complex 3 201.0 pm [3], in the homobimetallic 26 (M = Cr, n = 5) 206.6 pm [26] Coordinated or noncoordinated E (E = P, As, Sb) and E2 (E = P, As) atoms or molecules behave as donor groups also in transition metal complexes other than Co, giving cluster or open structures, e.g., [27,28,[75][76][77][78][79][80][81][82]. These interesting reports are beyond the scope of the present review.…”

Coordination Behavior of a P4‐Butterfly Complex towards Transition Metal Lewis Acids: Preservation versus Rearrangement

“…Here, regardless of the ring size, the oligophosphines always stabilize the metal center in a 1,3‐coordination mode. However, the highest diversity of coordination modes is found for phosphorus ligands that do not bear any organic substituents [1] . These so called P n ligands are usually obtained by reactions of white phosphorus (P 4 ) with either main group or transition metal moieties [15] .…”