'Product Blog'

Diphenylphosphine Selenide, Ph2HPSe is found more reactive in selenide formation than alternative reagents

The cost, reaction temperature,  yield, and synthetic reproducibility of colloidal particles with specific optical and electronic properties are  major challenges associated with the synthesis of II-VI and IV-VI colloidal semiconductor quantum dots (QDs) [e.g. 1-4]. Related issues were reviewed also in our previous blog on tri-n-octylphosphine (15-6655) and tri-n-octylphosphine oxide (15-6660, 15-6661).

The first fundamental study on the role of secondary phosphine, diphenylphosphine (DPP), in the promotion of particle yield was reported in 2006 [5]. Also, in later works, DPP showed useful reactivity for an enhancement of particle yield of small sized PbSe nanocrystals and the formation of alloyed PbSeS NCs [6-7]. At the same time, the secondary phosphine selenide, diphenylphosphine selenide (SeDPP or DPPSe, 15-1772), has been acknowledged to be more reactive than the tertiary phosphine selenide such as n-trioctylphosphine selenide (SeTOP) [8].

Fig. 1. Diphenylphosphine selenide, SeDPP or DPPSe, 15-1772

There are many interesting studies about the role and the reaction mechanism of DPPs in the literature. For example, Krauss et al [9] claimed that since the formation of Pb⁰ was unlikely at low reaction temperatures due to low reactivity towards SeTOP, he SeDPP is formed by way of Se exchange from SeTOP to DPP. It was reported that SeTOP was inert toward metal carboxylates and was only a soluble Se source. Without the addition of DPP, dioctylphosphine selenide (SeDOP) represented the very reactive species responsible for the formation of PbSe particles at low temperature. More recently, Kui Yu and Mingli Yang demonstrated an alternative view on tertiary and secondary phosphines on low-temperature formation of QDs [10]. Based on DFT calculations, they found that SeDPP, instead of SeTOP, reacts with Cd(OA)₂ at low temperature with high Cd-to-Se and Se-to-TOP molar ratios. The TOP coordination with Cd(OA)₂ and high SeDPP reactivity, shifts the equilibrium of SeTOP + DPP toward SeDPP.

Nowadays, DPPSe is a nearly irreplaceable component of Se-based quantum dot synthesis and has found useful applications in the preparation of PbSe [9, 11] ZnSe [8] and CdSe [12-14] quantum dots.

References:

1.    Nat. Nanotechnol. 2009, 4, 760.
2.    Nat. Nanotechnol. 2010, 5, 381.
3.    J. Am. Chem. Soc. 2006, 128, 13032.
4.    J. Am. Chem. Soc. 2009, 131, 10620.
5.    J. Am. Chem. Soc. 2006, 128, 13032.
6.    ACS Appl. Mater. Interfaces 2011, 3, 553.
7.    ACS Appl. Mater. Interfaces 2011, 3, 1511.
8.    ACS Appl. Mater. Interfaces 2012, 4, 4302.
9.    J. Am. Chem. Soc. 2010, 132, 10973.
10.    Angew. Chem. Int. Ed. 2013, 52, 4823.
11.    Nanoscale, 2015, 7, 5299.
12.    Chem. Phys., 2016, 471, 24.
13.    J. Phys. Chem. A 2016, 120, 918.
14.    J. Am. Chem. Soc. 2016, 138, 3382.
    
    

Products Mentioned in this Blog:

15-1772 Diphenylphosphine selenide, 98% (5853-64-5)

15-6655 Tri-n-octylphosphine, min. 97% TOP (4731-53-7)

15-6660 Trioctylphosphine oxide, min. 90% TOPO (78-50-2)

15-6661 Trioctylphosphine oxide, 99% TOPO (78-50-2)

Related Resources & Product Lines:

Nanomaterials

Phosphine

Ligands & Chiral Ligands

Phosphines for Colloidal Synthesis of Semiconducting Quantum Dots

Alkylphosphonic acids

Quantum Dots

Surfactants for Nano Synthesis