194140-74-4

Basic information

• Product Name: Aluminum, iodobis(2,2,6,6-tetramethyl-1-piperidinyl)-
• CAS NO: 194140-74-4
• Molecular Formula: C18H36AlIN2
• Molecular Weight: 434.383
• Mol File: 194140-74-4.mol
• Article Data: 2

Chemical Properties

• CAS DataBase Reference: Aluminum, iodobis(2,2,6,6-tetramethyl-1-piperidinyl)-(CAS DataBase Reference)
• NIST Chemistry Reference: Aluminum, iodobis(2,2,6,6-tetramethyl-1-piperidinyl)-(194140-74-4)
• EPA Substance Registry System: Aluminum, iodobis(2,2,6,6-tetramethyl-1-piperidinyl)-(194140-74-4)

Safety Data

• Hazardous Substances Data: 194140-74-4(Hazardous Substances Data)

Upstream product

• 7784-23-8 aluminium(III) iodide 
• 211381-92-9 (2,2,6,6-tetramethylpiperidino)2Al(γ-picoline) tetraiodoaluminate 

Relevant articles and documents

Bis(tetramethylpiperidino)aluminum Halide Adducts tmp2AlX·Do and Tetrahaloaluminates of Tricoordinated Aluminum Cations [tmp2Al(Do)]AlX4

Upon treatment with Lewis bases Do (Do = pyridine bases or THF), the Lewis acids tmp2AlX (X = Cl, Br, I) are converted exclusively to the monoadducts tmp2AlX·Do (2-4). The AlX bonds of these addition compounds are considerably elongated, indicating a tendency towards the formation of ionic species [tmp2Al(Do)]X. Due to the steric requirements of the bulky tmp ligands, addition of an excess of the Lewis base does not force these compounds to form tetracoordinated aluminum cations [tmp2Al(Do)2]+ or pentacoordinated adducts tmp2AlX·Do2. Attempts to prepare ionic representatives by reaction of tmp2AlX·Do with "ate" complexes of comparatively low nucleophilicity [MY = NaBPh4, AgBPh4, LiB(C6F5)4, AgBF4, AgOtos] result in phenylation products [e.g. tmp2AlPh (5a) and BPh3·py (5b)] or tetracoordinated addition compounds tmp2AlY·Do (Y = anion). However, addition of one equivalent of AlX3 (X = Br, I) initiates halide abstraction with formation of the ionic [tmp2Al(Do)]AlX4 species 6a-f, as indicated by 27Al-NMR data and conductivity measurements. Solid [tmp2Al(Py)]AlI4 (6b) decomposes readily into tmpAlI2 and tmpAlI2·py (7c) Addition of non-polar aliphatic solvents to solutions of [tmp2Al(Do)]AlX4 (6) leads to slow decomposition into tmp2AlX and AlX3·Do (7a-b, d). This also occurs in polar donor solvents, where compounds AlX3·Do are favoured due to the formation of penta- or hexacoordinated species AlX3·Do·Solvn (n = 1, 2). Semiempirical AM1 calculations reveal the gas-phase stability of the tricoordinated bis(tmp)aluminum cation in the salt [tmP2AlPy]AlCl4 as the only representative in a series of calculated aluminum cations [(R2N)2AlPy]AlCl4 (R2N = Me2N, Et2N, iPr2N, tmp). According to these calculations, the stability of a given cation increases when tetrachloroalummate is replaced by tetraiodoaluminate. Ab initio calculations have been performed on two cations [(H2N)2Al(Do)]+ (Do = NH3, py) and indicate very short Al-N bond lengths owing to ionic bonding contributions.