Homoleptic Isocyanide Metalates

Abstract

Novelties and surprises in the chemistry of metal isocyanides: The synthesis and structure determination of homoleptic isocyanide metalates [M(CNXyl) ] (M=Co, m=4; M=Mn, m=5; Xyl=2,6-Me C H ) indicate that we need to revise our understanding of transition metal-isocyanide interactions. Further investigations will be required to determine whether these salts with isocyanide metalate ions display a chemistry as rich as that of the analogous carbonyl metalates.

Aqueous Stability and Ligand Substitution of a Layered Cu(I)/Isocyanide-Based Organometallic Network Material with a Well-Defined Channel Structure

“…These interpenetrated layers stack along the a- axis to form the extended structure. As shown in Figure , there are two sets of parallel interpenetration within these discrete layers. − Along the b axis, two 2D sheets run parallel to each other in an interwoven manner and intersect at both Cu­(I) nodes and the central phenyl unit of the 1,4-(CNAr Mes2 ) 2 C 6 H 4 linker, while the other two parallel-interpenetrated sheets run in the opposite direction with identical intersection points.…”

“…Recently, we reported an approach to overcoming this challenge by using the rigid and linear ditopic m -terphenyl diisocyanide, [CNAr Mes2 ] 2 , as a linker group (Ar Mes2 = 2,6-(2,4,6-Me 3 C 6 H 2 ) 2 C 6 H 3 ; Scheme ). , Isocyanide ligands have long been recognized for their ability to function as both good σ-donors and strong π-acids, − which are properties that are particularly advantageous for the stabilization of electron-rich metal centers. − Accordingly, despite their charge neutrality, the dual bonding interactions provided by isocyanides lead to strong metal–ligand linkages that can be harnessed for reticular network formation. ,, It was shown that [CNAr Mes2 ] 2 could provide a series of robust, single-crystalline frameworks featuring Cu­(I)-based single-metal structural nodes (i.e., Cu- ISO CNs 1–3; ISO CN = isocyanide coordination network; Scheme ). In certain cases, these frameworks retain their thermal integrity up to ca.…”

A Well-Defined Isocyano Analogue of HCo(CO)4. 3: Hydride Migration to Olefins, H-Atom Transfer and Reactivity toward Protic Sources

“…Inspired by this extensive chemistry, we previously reported the synthesis, structural, and spectroscopic features of the m -terphenyl isocyanide complex HCo­(CNAr Mes2 ) 4 (Ar Mes2 = 2,6-(2,4,6-Me 3 C 6 H 2 ) 2 C 6 H 3 ), as a sterically encumbered and kinetically stabilized variant of HCo­(CO) 4 . Relying on the isolobal analogy between organoisocyanides and CO, − we conceived HCo­(CNAr Mes2 ) 4 as a potential structural and functional model of HCo­(CO) 4 . However, due to the fundamental differences between isocyanide and carbonyl ligation, ,, HCo­(CNAr Mes2 ) 4 also offered a potentially well-defined point of contrast to HCo­(CO) 4 from the standpoint of both electronic structure and function.…”

Crystalline Hydrogen-Bonding Networks and Mixed-Metal Framework Materials Enabled by an Electronically Differentiated Heteroditopic Isocyanide/Carboxylate Linker Group

“…Of these strategies, heteroditopic linkers offer unique advantages for the reliable formation of mixed-metal framework materials because two different binding groups can be specifically tuned to match the electronic requirements attendant between hard and soft metal centers. Recently, we introduced ditopic m -terphenyl isocyanides [CNAr Mes2 ] 2 and 1,4-(CNAr Mes2 ) 2 C 6 H 4 [Ar Mes2 = 2,6-(2,4,6-Me 3 C 6 H 2 ) 2 C 6 H 2 ] as linkers for MOF materials. − Isocyanides are electronically “soft” neutral ligands that function as good σ donors and effective π acids in a manner similar to that of CO. , While neutral in charge, isocyanides form robust M–L linkages on account of strong π-back-bonding interactions and are therefore adept at stabilizing low-valent metal centers. ,− As we have previously reported, ditopic m -terphenyl isocyanides can be employed for the formation of thermally robust and crystalline organometallic network materials featuring electron-rich metal centers [e.g., Cu­(I) and Ni(0)] as structural nodes. − However, isocyanides are particularly poor ligands for hard metals (e.g., Mg 2+ and Zn 2+ ) or metals in high formal oxidation states (e.g., Zr 4+ ). Seeking to exploit this disparate coordination behavior, we reasoned that heteroditopic ligands based on an isocyanide and an anionic binding group could offer a uniquely differentiated electronic environment for the formation of mixed-metal network materials.…”