The syntheses and NMR studies of hexadeca- and octaneopentoxyphthalocyanines

Bhardwaj, Namrta; Andraos, John; Leznoff, Clifford C.

doi:10.1139/v02-002

Cited by 25 publications

(14 citation statements)

References 19 publications

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“…Tetraalkoxyphthalonitriles can be readily made by nucleophilic aromatic substitution reactions of alkoxides on 3, 4,5,6-tetrafluorophthalonitrile (l) [9,10], even with very bulky alkoxides [0]. Thus treatment of I with neopentyl alcohol or cyclohexylmethanol in lr',Ir'-dimethyl formamide neopentoxyphthalonitrile (2) or 3,4,5,6-tetra(cyclohexylmethyloxy)phthalonitrile (3), respectively.…”

Section: Resultsmentioning

confidence: 99%

“…In this spirit, in previous res€arch in the Lezno$ group, very bulky neopenloxy groups have been used to cause a red-shift in the Q-band region of the UV-Vis spectra of Pcs [0], such that hexadecaneopentoxyphthalocyanine nickel(Il) had the lowest energy Qlband yet recorded for an alkoxy-substituted metallated Pc, at 758 nrn. In addition, these bulky peripheral groups disrupt n-stacking between macrocyctes and therefore increase the solubility of the substituted Pcs even in non-polar solvents such as hexanes.…”

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“…In addition, these bulky peripheral groups disrupt n-stacking between macrocyctes and therefore increase the solubility of the substituted Pcs even in non-polar solvents such as hexanes. Although the preparation of hexadecaneopentoxy phthalocyanine nickel has been described previously [0] As Hanack had shown [9] that only bulky Pcs containing nickel can be readily prepared and since removal of .the nickel is difficult to accomplish without decomposition, other metallated or metal-free bulky alkoxy Pcs were not easily prepared. We tried many established methods [7] as well as newer methods I I -14] usually to no avail.…”

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“…In this paper, we report the full details of the red phthalocyanines, bearing t6 bulky alkoxy substituents and a manganesc core. 3,4,5,6.7e lraneopento xyph t halonitr ile ( 2 ) Compound 2 was prepared according to a previously described procedure [0]. 2.…”

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Red manganese phthalocyanines from highly hindered hexadecaalkoxyphthalocyanines

Leznoff

Black

Hiebert

et al. 2006

Inorganica Chimica Acta

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Dediated to Bdau Jam6 on the occasion of his 70tb birthday. AbstractHighly hindered magnesium and metal-free green 1,2,3,4,8,9,10,1 l,l5,l6,l7,l 8,22,23,24,25'hexadecaneop€ntoxyphthalocyanine and t,Z,:,1,A,S,f0,tt,15,16,11,18,22,23,24,25-hexadeca(cyclohexylmethylor.y)phthalocyanine were prepared via magnesium l-octanolate and 3,4,5,6+etraneopentoxyphthalonitrile or 33,5,6-tetra(cyclohexylmethyloxy) The inertness ofPcs is well known [3], but their classical use as dyes [3] is now overshadowed by other applications taking advantage of the inlense absorption of the Q-band' normally between 670 and 730 nrn. Highly red-shifted anatogs of Pcs,-having additional benzo groups attached to the Pc benzo groups (the naphthalocyanines and even anthracenocyanines [4] are usually difficult to prepare, highly insoluble, and prone to decomposition [5]. It has long been known that Pcs containing electron-donating substituents at the 1,4,8,! 1,15,18,22,25 substituents) show some red-shifts of the Pc chromophore, but that only minor shifts occur due to substituents placed at the 2, 3,9,10,16,17,23,24 positions (the peripheral substituents) [6][7][8]. On the other hand some hexadecaalkoxysubstituted Pc nickel cornpounds exhibited enhanced red shifts, showing a Q-band shifted to as long a wavelength as 745 nm [9]. It appears that the substituents at the peripheral positions buttress the substituents at the non-peripheral posilions effeotively making the non-peripheral substituents bulkier.In this spirit, in previous res€arch in the Lezno Further reduction at -1.6V versus Fc*/Fc (Fig. 3) yiolds a spectrum consistent with expectation for a Pc(3-) radical anion t2l-241 Curiously, the absorption bands in the 700 nm region for this species are closely similar to those of the Mnl! precursor. There is growth ol a weak band near 900 nm. The electrochemical data shown in Fig. 4 Spectroelectrochem.istry, discussed below, shows that peak I (Fig. 4) (Fig. 4! ihe nature of the second species was not further studied.Oxidation at peak VI yielded a spectrum (Fig. 9) typical P2-24,26) of tn-e radical cation phthalocyanino(l-) species, and hence the formation of [NeoPdl-)Mnlv absorption between 500 and 600 nm to which we return in Section 3.5. The Mn(II)Pc(3-) spectra are also targely similar with three peaks in the visible region and a weak absorption around 900 nrn. This provides a means to change the counter axial anion by simply changing the acid used. The counter-ion does, as expected, have a small but noticeable eflect on the spectrum. Table I Variation of axial counter-ion

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Red manganese phthalocyanines from highly hindered hexadecaalkoxyphthalocyanines

Leznoff

Black

Hiebert

et al. 2006

Inorganica Chimica Acta

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“…The synthesis of sy.mmetrical tetra [3][4][5][6], oct^ 17-91, and even hexadecaphthalocyanine (Pcs) [10][11][12] are relatively straightforward using an appropriately substituted phthalonitrile as the sole precursor. In most examples these phthalonitrile precursors consist of phthalonitriles containing only one substituent at the 3-or 4-position or disubstituted phthalonitriles having two identical substituent$ on the 4,5-or 3,6-positions, but in one unusual example at the 3,4-position [3].…”

Section: Introductionmentioning

confidence: 99%

Multisubstituted phthalonitriles for phthalocyanine synthesis

Wang

Khanamiryan

Leznoff

2004

J. Porphyrins Phthalocyanines

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3,4,5,6+etrafluorophthalonitrile and 33,5,6-tetrachlorophthalonitrile were used as substrates with various phenoxides to pfepare 3,4,6-trihalo-5-p-substitutedphenoxyphthalonitriles, containing four substituonts other than hydrogen, by nucleophilic arornatic substitution reactions.Subsequent reactions with unsymmetrical catechols gave tetrasubstitutedphthalonitriles, having four different substituents. In one instance, anempts to displace the last remaining fluoro group by an octanoxide nucleophile led to substitution of a p-methylphenoxy group, showing that phenoxy substituents are also labile in nucleophilic aromatic substitution reactions on phthalonitriles.Alternatively, 4,5-dimethoxyphthalonitrile or 4,5-dineopentoxyphthalonitrile underwent elechophilic aromatic substitution reactions with dibromoisocyanuric acid to give their respective 3,6-dibromophthalonitriles. Coupling of these bromophthalonitriles with tri(n-butyl)phenylylethynyltin and tri(n-butyl)vinyltin in the presence of a nickel catalyst gave 4,5-dimetftoxy-3,6-bisphenylethy nylphthalonitrile, 3-bromo-4,5-dimethoxy{-phenylethynylphthalonitrile, 4,5-dineopentoxy-3,6-bisphenylethynylphthalonitrile, 3-brsmo4,5dineopentoxy-6phenylethynylphthalonitrile, 4,5-dirnethoxy-3,6-vinylphthalonitrile and 3-bromo-4,5dimethoxy-6-vinylphthalonitrile. Reductions in the coupling steps sometimes led to 4,5-dimethoxy-3-phenylethynylphthalonitrile and4,5-dimethoxy-3-vinylphthalonitrile.

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Porphyrin Atropisomerism as a Molecular Engineering Tool in Medicinal Chemistry, Molecular Recognition, Supramolecular Assembly, and Catalysis

Maguire,

Strachan,

Norvaiša

et al. 2024

Chemistry A European J

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Porphyrin atropisomerism, which arises from restricted σ‐bond rotation between the macrocycle and a sufficiently bulky substituent, was identified in 1969 by Gottwald and Ullman in 5,10,15,20‐tetrakis(o‐hydroxyphenyl)porphyrins. Henceforth, an entirely new field has emerged utilizing this transformative tool. This review strives to explain the consequences of atropisomerism in porphyrins, the methods which have been developed for their separation and analysis and present the diverse array of applications. Porphyrins alone possess intriguing properties and a structure which can be easily decorated and molded for a specific function. Therefore, atropisomerism serves as a transformative tool, making it possible to obtain even a specific molecular shape. Atropisomerism has been thoroughly exploited in catalysis and molecular recognition yet presents both challenges and opportunities in medicinal chemistry.

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The syntheses and NMR studies of hexadeca- and octaneopentoxyphthalocyanines

Cited by 25 publications

References 19 publications

Red manganese phthalocyanines from highly hindered hexadecaalkoxyphthalocyanines

Red manganese phthalocyanines from highly hindered hexadecaalkoxyphthalocyanines

Multisubstituted phthalonitriles for phthalocyanine synthesis

Porphyrin Atropisomerism as a Molecular Engineering Tool in Medicinal Chemistry, Molecular Recognition, Supramolecular Assembly, and Catalysis

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