Cadmium Compounds with an [N₃C] Atrane Motif: Evidence for the Generation of a Cadmium Hydride Species

Abstract

Tris(2-pyridylthio)methane ([Tptm]H) has been employed to synthesize a series of cadmium carbatrane compounds that feature an [N3C] coordination environment. Specifically, [Tptm]H reacts with Cd[N(SiMe3)2]2 to afford [Tptm]CdN(SiMe3)2, which thereby provides access to other derivatives. For example, [Tptm]CdN(SiMe3)2 reacts with (i) CO2 to form {[Tptm]Cd(μ-NCO)}2 and (ii) Me3SiOH and Ph3SiOH to form {[κ3-Tptm]Cd(μ-OSiMe3)}2 and [Tptm]CdOSiPh3, respectively. The siloxide compound {[κ3-Tptm]Cd(μ-OSiMe3)}2 reacts with Me3SiX (X = Cl, Br, O2CMe) to give [Tptm]CdX, while the reaction with PhSiH3 in the presence of CO2 generates the formate complex, [Tptm]CdO2CH, thereby providing evidence for the generation of a proposed cadmium hydride intermediate, {[Tptm]CdH}.

Mechanistic insight into copper cation exchange in cadmium selenide semiconductor nanocrystals using X-ray absorption spectroscopy

“…Values for CN O tend to asymptote near 5-6, which suggest some form of a five- or six-fold coordinate Cd 2+ complex. We note that we cannot exactly quantify the state of the Cd byproduct but the derived bond lengths ( R CdO ~ 2.3 Å) support the existence of a five- or six-fold coordinate Cd species bonded to a low- Z element 24 . The values for R CdSe and R CuSe are both remarkably consistent throughout the concentration steps, again supporting the observation of a two phase process, as severe structural perturbations or the creation of new phases could lead to much larger deviations in the derived bond lengths 25 .…”

Preparation and properties of uncommon Cd‐Mn carboxylate complexes—per se and as precursors for CdMn2O4‐based ceramics

“…Compared to widely applied synthetic techniques involving common cadmium salts, that is, nitrate/acetate, [ 8i ; 11a,c ] the method with an acetylacetonate is more flexible. A probable stepwise acac − to RCOO − substitution (see above) enriches the opportunities of the method, already vast due to a variety of possible coordination modes of RCOO − and to the ability to involve auxiliary ligands.…”

“…Such a range of valuable properties obviously originates from a great structural variety of Cd carboxylates involving mononuclear [ 8a–c ] and oligonuclear complexes [ 8d–h ] as well as coordination polymers (CPs) of different dimensionalities. [ 8i–l ] All these structural motifs, in turn, are possible due to well‐known rich coordination abilities of carboxylate ligands. Even more motifs for carboxylate complexes can be designed using various auxiliary ligands, capable to block or to promote the assembly of polynuclear structures.…”

“…However, there is also a small group of heterometallic carboxylates comprising one of the metals not as corresponding M n+ but as a part of a stable organometallic ligand bearing carboxylate group and which thus may be regarded as “organometallic Cd carboxylates” (OCCs). Among OCCs, ferrocene derivatives (ferrocene = ( η 5 ‐C 5 H 4 ) 2 Fe) form the vast majority [ 8b,g ; 11a ; 14a–d ] , and very few complexes with Cr‐ [ 8c , 14e ] and Co‐containing carboxylate anions [ 8f , 14f–h ] are known up to date. Meanwhile, carboxylate derivatives of Cd 2+ comprising other stable metalloorganic moiety, namely, cymantrenyl one (cymantrene = Cym = ( η 5 ‐C 5 H 4 )Mn (CO) 3 ) still remain virtually undiscovered.…”

Synthesis of bis(2-pyridylthio)methyl zinc hydride and catalytic hydrosilylation and hydroboration of CO2

“…In addition to simple metathesis reactions, the Zn–N bond is also subject to insertion of CO 2 to generate the isocyanate derivative [Bptm]ZnNCO (Scheme 2) via a sequence that is proposed to occur via the initial insertion of CO 2 into the Zn–N(SiMe 3 ) 2 bond. 12 The most significant reactivity of [Bptm]ZnN(SiMe 3 ) 2 , however, is that it enables the synthesis of the zinc hydride complex, [Bptm]ZnH, upon treatment with pinacolborane (HBpin) at room temperature. The formation of [Bptm]ZnH by the use of HBpin is of note because Zn–N(SiMe 3 ) 2 bonds are not typically cleaved by hydrosilanes at room temperature to afford terminal hydride compounds; for example, elevated temperatures are employed to achieve the reaction of Zn[N(SiMe 3 ) 2 ] 2 with PhSiH 3 in the presence of IPr.…”