Accessing Pentagonal Bipyramidal Geometry with Pentadentate Pincer Amido-bis(amidate) Ligands in Group IV and V Early Transition Metal Complexes

Palomero, Orhi Esarte; Jones, Richard A.

doi:10.1021/acs.organomet.0c00501

Cited by 5 publications

(3 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hafnium congeners attract much less attention and only very few derivatives have been authenticated by solid-state structures. 17 Contrary to the adamantylamidate in 2, 3, and 4, even rather bulky amidate ligands form isostructural compounds for titanium and zirconium (entries 1/10, 6/11, 7/12, 8/13, and 9/14). In complexes with hexa-coordinate group IV metals, the M−O bond lengths are smaller than the M−N distances due to the oxophilic character of the metal ions.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…Complexes with additional ring strain by bridging benzo and biaryl , fragments are omitted in this table. Hafnium congeners attract much less attention and only very few derivatives have been authenticated by solid-state structures . Contrary to the adamantylamidate in 2 , 3 , and 4 , even rather bulky amidate ligands form isostructural compounds for titanium and zirconium (entries 1/10, 6/11, 7/12, 8/13, and 9/14).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Group IV Complexes with Sterically Congested N-Aryl-adamantylcarbamidate Ligands

Kheirkhah,

Huadsai,

Liebing

et al. 2023

Organometallics

View full text Add to dashboard Cite

Metalation of N-(2,6-dibenzhydryl-4-tolyl)adamantane-1-carboxamide (1, Ar*N(H)–C(O)–Ad) with M(NMe2)4 (M = Ti, Zr, Hf) yields amidate complexes Ar*N=C(Ad)–O–Ti(NMe2)3 (2) as well as bis(amidate) compounds (Ar*N=C(Ad)–O)2M(NMe2)2 (M = Zr (3), Hf (4)). In 2, the amidate ligand acts as a monodentate base via the oxygen atom with the Ti center in a slightly distorted tetrahedral environment. The steric requirement of the amidate ligand stabilizes the small coordination number of four of the Ti atom. In congeners 3 and 4, two bidentate amidate ligands exist in the coordination spheres, leading to hexacoordinate group IV metal atoms. The small bite angles of the Zr- and Hf-bound amidate ligands lead to severe distortion of the octahedral environments of the Zr and Hf centers. Titanium compound 2 is an unsuitable choice to catalyze hydrofunctionalization of alkynes with amines and phosphane oxides and despite the significantly smaller pK a value of the carboxylic amide, formation of carboxamide 1 is the dominant reaction upon addition of amines or phosphane oxides to release intramolecular steric strain introduced by the very bulky adamantylamidato ligand.

show abstract

Section: ■ Results and Discussionmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Group IV Complexes with Sterically Congested N-Aryl-adamantylcarbamidate Ligands

Kheirkhah,

Huadsai,

Liebing

et al. 2023

Organometallics

View full text Add to dashboard Cite

show abstract

“…The 31 P{ 1 H} NMR spectrum in the region of the coordinated dppe shows a set of signals slightly shifted to 57.9 ppm, which is attributed to heteroleptic complex 9b (Scheme ) or monosubstituted Rh/Ti complex formed by loss of a [Rh(dppe)] + fragment, whose signal was detected by HRMS at 1725.5083 m / z . Decomposition of the Ti amidate bond might be related to the extreme sensitivity of these complexes, which can react with adventitious traces of water in solution, releasing TiO 2 . , Reacting 3b with 8 in fluorobenzene at RT for 1 h gives conversion of 3b to [Rh(dppe)(C 6 H 5 F)][B Ar F ] (doublet at 73.5 ppm, 1 J Rh-P = 204 Hz) while no traces of 10b were found. Heating the reaction mixture to 80 °C for 10 min results in a subtle color change to burnt orange and full conversion to heterobimetallic 10b .…”

Section: Resultsmentioning

confidence: 99%

Heterobimetallic Complexes of 1,1-Diphosphineamide Ligands

et al. 2021

View full text Add to dashboard Cite

We herein discuss the use of 1,1-diphosphineamide ligands for the synthesis of mono-and heterobimetallic complexes of Rh(I) and Ti(IV) metal centers. A small library of monometallic species was synthesized and isolated: Ti was used to complex to the amide moiety, whereas Rh was used to bind to the diphosphine. The sequential synthesis of the heterobimetallic species started from isolation of the Ti(amidate) complex followed by addition of Rh precursors in solution. Meticulous analysis of the complexes by NMR spectroscopy allowed stereometric and spatial recognition of these challenging to synthesize and isolate heterobimetallic complexes.

show abstract

Silyl‐Substituted ortho‐Terphenoxide Group 3–5 Complexes: Synthesis, Structure and Applications in Catalysis

Polak,

Soltys,

Hultzsch

2024

Eur J Inorg Chem

View full text Add to dashboard Cite

The complexation behavior of 3,3’‐silyl‐substituted ortho‐terphenoxide ligands o‐C6H4(C6H2‐2‐OH‐3‐SiR3‐5‐Me)2 (SiR3= SiPh3, SiMePh2, SiMe3, Sit‐BuMe2) with a range of yttrium, titanium, niobium and tantalum precursors was examined. The complexation of the ligands with Y(N(SiHMe2)2)3(THF)2 yielded monomeric complexes, as confirmed by NMR spectroscopy and X‐ray crystallography for the methyldiphenylsilyl‐ and tert‐butyldimethylsilyl‐substituted complex. The triphenylsilyl‐substituted yttrium bisdimethylsilylamido complex showed good activity in the intramolecular hydroamination reaction of aminoalkenes. Complexation with Ti(NMe2)4 yielded a mixture of products, depending on the silyl substituents and the solvent used for complexation. A mono‐ligated bimetallic titanium complex and a bisligated titanium complex were analyzed by X‐ray crystallography. Complexation with M(NMe2)5 (M = Nb, Ta) produced the corresponding monomeric ortho‐terphenoxide complexes as confirmed by NMR spectroscopy and X‐ray structure analysis analysis of a niobium complex and 3 tantalum complexes.

show abstract

Accessing Pentagonal Bipyramidal Geometry with Pentadentate Pincer Amido-bis(amidate) Ligands in Group IV and V Early Transition Metal Complexes

Cited by 5 publications

References 55 publications

Group IV Complexes with Sterically Congested N-Aryl-adamantylcarbamidate Ligands

Group IV Complexes with Sterically Congested N-Aryl-adamantylcarbamidate Ligands

Heterobimetallic Complexes of 1,1-Diphosphineamide Ligands

Silyl‐Substituted ortho‐Terphenoxide Group 3–5 Complexes: Synthesis, Structure and Applications in Catalysis

Contact Info

Product

Resources

About