Group 13/15 multiple bonds

Heteroatomic multiple bonding between group 13 and group 15 elements are of great interest in synthetic chemistry due to their isoelectronicity with C-C multiple bonds. Nevertheless, the difference of electronegativity between group 13 and 15 leads to different character of bondings comparing to C-C multiple bonds. Because of the ineffective overlap between p𝝅 orbitals and the inherent lewis acidity/basicity of group 13/15 elements, the synthesis of compounds containing such multiple bonds is challenging and subject to oligomerization.[1][2] The most common example of compounds with 13/15 group multiple bonds are those with B=N units. The boron-nitrogen-hydride compounds are candidates for hydrogen storage.[3][4][5] In contrast, multiple bonding between aluminium and nitrogen Al=N, Gallium and nitrogen (Ga=N), boron and phosphorus (B=P), or boron and arsenic (B=As) are less common.[2]

Synthesis

P(R)=BMes2Li(Et2O)2 (R = phenyl, cyclohexane, mesitylene)[6]

Suitable precursors are crucial for the synthesis of group 13/15 multiple bond-containing species. In most successfully isolated structures, sterically demanding ligands are utilized to stabilize such bondings.

Boraphosphenes (P=B)

Boraphosphenes, also known as phosphoboranes, was first reported by Cowley and co-workers in the 1980s.[7] [(tmp)B=P(Ar)] (tmp= 2,2,6,6,-tetramethylpiperidina, Ar= 2,4,6-t-Bu3C6H2) was characterized by mass spectroscopy (EI MS), and the corresponding dimer, diphosphadiboretane, was characterized by X-ray crystallography.[7] The Power and co-workers later reported the structure of [P(R)=BMes2Li(Et2O)2] (R = phenyl, cyclohexane, and mesitylene), which is the first B=P double bond observed in solid state.[6] The synthesis of [P(R)=BMes2Li(Et2O)2] starts from treating in-situ generated Mes2BPHR with 1 equivalent of t-BuLi in Et2O, followed by crystallization at low temperature.[6]

Cyclic system with P-B multiple bonds

Photo-induced isomerization of cycle-[(iPr)2PB(tBu)-B(tBu)-P(Ph)2][8]

Isomerization of four-member P-B cycles was investigated by Bourissou and Bertrand. It was reported that cycle-[R2PB(R')-B(R')-P(Ph)2] (R = phenyl, isopropyl; R'= tert-butyl, 2,3,5,6-tetramethyl phenyl) isomerize to form cycle-[R2P-B(R')=P(Ph)-B(R')(Ph)] upon irradiation.[8] An example of five-membered ring was reported by Crossley suggesting that a reaction of 1,2-diphosphinobenzene with n-BuLi and Cl2BPh yielded a benzodiphosphaborolediide.[9] Several six-membered ring systems involving P=B double bonds have been reported. One of the example is an analogue of borazine synthesizing from MesBBr2 and CyP(H)Li.[10]

Synthesis of a borazine analogue containing P=B bonds[11]
Synthesis of a benzodiphosphaborolediide[9]

Arsinideneborates (As=B)

A similar strategy to access litigated arsinideneborate was reported by Power and co-workers after the establishment of synthesizing litigated phosphinideneborates.[12] Crystallizing [As(Ph)=BMes2Li(THF)3] with two equivalence of TMEDA yielded [As(Ph)=BMes2][Li(TMEDA)2].[12] Ring-systems containing As-B multiple bonds haven't been reported yet.

Synthesis of [{DipNacnc}M=N-TipTer] (M=Al, Ga)[13] and [(DipTer)M=N-Mes'Ter] (M=Ga, In)[14]

Group 13 imides (Al=N, Ga=N, In=N)

Synthesis of group 13 imides usually starts with low valent group 13 species stabilized by bulky ligands. A [2+3] cycloaddition of monomeric [DipNacnc]Al or [DipNacnc]Ga (DipNacnc= HC{(CMe)(NDip)}2) compound with sterically bulky azide, TipTerN3 (TipTer = -C6H3-2,6-(C6H2-2,4,6-iPr3)2), gives the iminotrielenes [{DipNacnc}M=N-TipTer] (M=Al, Ga).[15] Additionally, dimers of Ga(I) or In(I) were reported to form the iminotrielens [(DipTer)M=N-Mes'Ter] with Mes'TerN3 (M = Ga, In; Mes'Ter =C6H3-2,6(Xyl-4-tBu)2).[16]

Al-N triple bonds

Synthesis of DipTerPnAlCp* (Pn = P, As)[17]

Transient Al≡N triple bond species were also investigated by reacting monomeric alanediyl precursor with organic azides. The unstable Al≡N triple bond species [iPr2TIPTerAl≡NR] (R = Ad, SiMe3) was not capture but further rearrange to tetrazole and amino-azide alone, respectively.[18]

Phosphaalumenes and Arsaalumenes (P=Al, As=Al)

The development of Al=P and Al=As species faced the difficulty due to the tendency of oligomerization of the lewis acidic Al and lewis basic P/As. In 2021, Hering-Junghans, Braunchweig, and co-workers reported the synthesis of phosphaalumens and arsaalumens with Al(I) precursors, [Al(I)Cp*]4 (Cp* = pentamethylcyclopentadiene). Reacting [Al(I)Cp*]4 with DipTer-AsPMe3 or DipTer-AsPMe3 at 1:4 ratio yielded the corresponding phosphaalumens/arsaalumens, which are stable and isolable.[19]

Gallium-pnictogen double bonds (Ga=Pn)

DipNacnc(Cl)Ga}}2Sb[21]

Synthesis and characterization of Ga=Sb species was reported by Schulz and Cutsail III with the reaction of [DipNacnc]Ga (DipNacnc= HC{(CMe)(NDip)}2) with [Cp*SbCl2]. The resulting Sb radical species, [DipNacnc(Cl)Ga]2Sb, was then reduced by KC8 to give [DipNacncGa=Sb-Ga(Cl)DipNacnc].[21] Utilizing the similar reaction pathway, a Ga=As species, [DipNacncGa=AsCp*], was successfully synthesized and stabilized. Interestingly, no radical formation was observed comparing to the case of Ga=Sb species.[20] With the rapid development of gallium pnictogen in the late 2010s, the first phosphagallene species was reported by Goicoechea and co-workers in 2020. The reaction of [(HC)2(NDip)2PPCO] with [DipNacncGa] gave the phosphagallene, [DipNacncGa=P-P(NDip)2(CH)2].[22]

Reactivities

C-F activation of tris(pentafluorophenyl)borane by [(tmp)(L)B=PMes*] (L = IMe4)[23]

Reactivities of boraphosphenes

B=P double bond species has been studied for bond activation. For example, C-F activation of tris(pentafluorophenyl)borane by NHC-stabilized phosphaboranes, [(tmp)(L)B=PMes*] (L = IMe4), was reported by Cowley and co-workers.[23] The C-F bond activation takes place at the para position, leading to the formation of C-P bond.[23] Reactions of phenyl acetylene with the dimer of [Mes*P=B(tmp)] give an analogue of cycle-butene, [Mes*P=C(Ph)-C(H)=B(tmp)], where C-C triple bond undergoes a [2+2]-cycloaddition to P=B double bond.[23]

Phospha-bora Wittig reaction

Phospha-bora Wittig reaction[24]

Transient boraphosphene [(tmp)B=PMes*)] (tmp = 2,2,6,6-tetramethylpiperidine, Mes* = 2,4,6-tri-tert-butylphenyl) reacts with aldehyde, ketone, and esters to form phosphaboraoxetanes, which converts to phosphaalkenes [Mes*P=CRR'] and [(tmp)NBO]x heterocycles.[25][24] This method provides direct access of phosphaalkenes from carbonyl compounds.[25][24]

Reactivities of group 13 imides

Compounds with group 13-N multiple bonds are capable of small molecule activation. Reactions of PhCCH or PhNH2 with NHC-stabilized iminoalane result in the addition of proton to N and -CCPh or -NHPh fragment to Al.[26] The reaction with CO leads to the insertion of CO between the Al=N bond.[26]

Reactivities of Ga=Pn species

Polar bonds activation by [DipNacnc(RN)Ga-P-P(H)(NDip)2(CH2)2][2][27]

Small molecule activation takes place across the P-P=Ga bonds in phosphanyl-phosphagallenes species, where the Ga=P species behave as frustrated Lewis pairs. For example, the reaction of CO2 with [DipNacncGa=P-P(NDip)2(CH2)2] results in the formation of a P=P-C-O-Ga five-membered ring species. In contrast, H2 addition to the P-P=Ga fragment in a 1,3-activation manner.[22] E-H bond activation of protic and hydridic reagents was investigated as well. Reactions of [DipNacncGa=P-P(NDip)2(CH2)2] toward amines, phosphines, alkynes resulted in the formation of [DipNacnc(E)Ga-P-P(H)(NDip)2(CH2)2].[2] Reversible ammonia activation was observed under 1 bar pressure in the presence of a Lewis acid.[2]

Bonding and structures

B=P double bond

Natural bond orbital analysis of a borophosphide anion, [(Mes*)P=BClCp*]-, suggested that the B-P double bonds are polarized to the P atom. The B=P 𝝈-bond is mostly non-polar while the 𝝅-bond is polarized to the phosphorus (71%).[28] DFT calculation at B3LYP/6-31G level revealed that the HOMO of [(Mes*)P=BClCp*]- has great B-P 𝝅-bonding character.[28] In most reported phosphinideneborates, the phosphorus chemical shifts are much more deshielded than the starting materials, phosphinoboranes. The down-field resonances of phosphorus in 31P NMR suggest the delocalization of lone pairs into the empty p-orbital of boron.[28]

Selected NMR chemical shifts (ppm) and bond length (pm) of anionic compounds with B=P bond
Compound 11B NMR 31P NMR d(B-P)
[P(Cy)=BMes2Li(Et2O)2][29] 65.6 70.1 183.2(6)
[P(Mes)=BMes2Li(Et2O)2][30] 63.7 55.5 182.3(7)
[P(Ad)=BMes2Li(Et2O)x][31] 85.7 90.4 182.3(8)
[P(tBu)=BTip2Li(Et2O)2][32] 58.9 113.2 183.6(2)
[P(SiMe3)=BMes2Li(THF)3][33] 71.7 -49.2 183.3(6)
Selected NMR chemical shifts (ppm) and bond length (pm) of Lewis acid/base stabilized compounds with B=P bond[1]
Compound 11B NMR 31P NMR d(B-P)
[Cr(CO)5{(tmp)B=PC(Et)3}[34] 62.9 -45.3 174.3(5)
[AlBr3{(tmp)B=P(tBu)}][35] 68.4 -59.8 178.7(4)
[(tmp)(DMAP)B=PTipTer][36] 41.2 57.3 180.92(17)
[Cp*(DMAP)B=PMes*][37] 52.3 96.7 179.5(3)
[Cp*(IMe4)B=PMes*][38] 48.5 192.9 180.67(15)
[Cp*B(Br)=PMes*][IiPrSiMe3][39] 54.9 75.2 180.39(16)
[(tmp)(DMAP)B=PMes*][40] 44.5 64.0 182.11(16)
[(tmp)(IMe4)B=PMes*][41] 43.9 151.5 183.09(16)

Ga-Pn double bond

Natural bond orbital analysis was reported for Ga=Sb and Ga=Bi containing species, where electron populates more on Sb and Bi (62% and 59%, respectively). The Lewis acidic Ga results in the delocalization of electrons in Sb and Bi.[21]

References

  1. ^ a b Dankert, F.; Hering-Junghans, C. (2022). "Heavier group 13/15 multiple bond systems: synthesis, structure and chemical bond activation". Chemical Communications. 58 (9): 1242–1262. doi:10.1039/D1CC06518A. ISSN 1359-7345. PMID 35014640.
  2. ^ a b c d e Feld, Joey; Wilson, Daniel W. N.; Goicoechea, Jose M. (2021-08-31). "Contrasting E−H Bond Activation Pathways of a Phosphanyl‐Phosphagallene". Angewandte Chemie. 133 (40): 22228–22232. doi:10.1002/ange.202109334. ISSN 0044-8249.
  3. ^ Huang, Zhenguo; Autrey, Tom (2012-10-18). "Boron–nitrogen–hydrogen (BNH) compounds: recent developments in hydrogen storage, applications in hydrogenation and catalysis, and new syntheses". Energy & Environmental Science. 5 (11): 9257–9268. doi:10.1039/C2EE23039A. ISSN 1754-5706. S2CID 97314459.
  4. ^ Rossin, Andrea; Peruzzini, Maurizio (2016-04-14). "Ammonia–Borane and Amine–Borane Dehydrogenation Mediated by Complex Metal Hydrides". Chemical Reviews. 116 (15): 8848–8872. doi:10.1021/acs.chemrev.6b00043. ISSN 0009-2665. PMID 27075435.
  5. ^ Dosso, Jacopo; Battisti, Tommaso; Ward, Benjamin D.; Demitri, Nicola; Hughes, Colan E.; Williams, P. Andrew; Harris, Kenneth D. M.; Bonifazi, Davide (2020-03-24). "Boron–Nitrogen‐Doped Nanographenes: A Synthetic Tale from Borazine Precursors". Chemistry – A European Journal. 26 (29): 6608–6621. doi:10.1002/chem.201905794. hdl:11368/3035326. ISSN 0947-6539. PMID 32023358. S2CID 211045410.
  6. ^ a b c Bartlett, Ruth A.; Feng, Xudong.; Power, Philip P. (October 1986). "Synthesis and characterization of the phosphinidene borate complexes [Li(Et2O)2PRB(Mes)2] and [Li(12-crown-4)2][RPB(Mes)2].cntdot.THF [R = Ph, C6H11 or Mes (Mes = 2,4,6-Me3C6H2)]: the first structurally characterized boron-phosphorus double bonds". Journal of the American Chemical Society. 108 (21): 6817–6819. doi:10.1021/ja00281a067. ISSN 0002-7863.
  7. ^ a b Arif, Atta M.; Boggs, James E.; Cowley, Alan H.; Lee, Jung Goo.; Pakulski, Marek.; Power, John M. (September 1986). "Production of a boraphosphene (RB:PR') in the vapor phase by thermolysis of a sterically encumbered diphosphadiboretane". Journal of the American Chemical Society. 108 (19): 6083–6084. doi:10.1021/ja00279a091. ISSN 0002-7863. PMID 22175399.
  8. ^ a b Bourg, Jean-Baptiste; Rodriguez, Amor; Scheschkewitz, David; Gornitzka, Heinz; Bourissou, Didier; Bertrand, Guy (2007-07-23). "Thermal Valence Isomerization of 2,3-Diborata-1,4-diphosphoniabuta-1,3-dienes to Bicyclo[1.1.0]butanes and Cyclobutane-1,3-diyls". Angewandte Chemie International Edition. 46 (30): 5741–5745. doi:10.1002/anie.200701578. PMID 17592605.
  9. ^ a b Pearce, Kyle G.; Canham, Elinor P. F.; Nixon, John F.; Crossley, Ian R. (2021-11-25). "A Benzodiphosphaborolediide". Chemistry – A European Journal. 27 (66): 16342–16346. doi:10.1002/chem.202103427. ISSN 0947-6539. PMID 34586681. S2CID 238218283.
  10. ^ Dias, Power, H. V. Rasika, Philip P. (December 1987). "Synthesis and X-Ray Structure of (2,4,6-Me3C6H2BPC6H11)3: A Boron-Phosphorus Analogue of Borazine". Angew. Chem. Int. Ed. Engl. 26 (12): 1270–1271. doi:10.1002/anie.198712701.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  11. ^ Dias, H. V. Rasika; Power, Philip P. (December 1987). "Synthesis and X-Ray Structure of(2,4,6-Me3C6H2BPC6H11)3: A Boron-Phosphorus Analogue of Borazine". Angewandte Chemie International Edition in English. 26 (12): 1270–1271. doi:10.1002/anie.198712701. ISSN 0570-0833.
  12. ^ a b Petrie, Shoner, Dias, Power, Mark A., Steven C., H. V. Rasika, Philip P. (September 1990). "A Compound with a Boron–Arsenic Double Bond". Angew. Chem. Int. Ed. Engl. 29 (9): 1033–1035. doi:10.1002/anie.199010331.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  13. ^ Hardman, Ned J.; Cui, Chunming; Roesky, Herbert W.; Fink, William H.; Power, Philip P. (2001-06-01). <2230::aid-ange2230>3.0.co;2-n "Stable, Monomeric Imides of Aluminum and Gallium: Synthesis and Characterization of [{HC(MeCDippN)2}MN-2,6-Trip2C6H3] (M=Al or Ga; Dipp=2,6-iPr2C6H3; Trip=2,4,6-iPr3C6H2)". Angewandte Chemie. 113 (11): 2230–2232. doi:10.1002/1521-3757(20010601)113:11<2230::aid-ange2230>3.0.co;2-n. ISSN 0044-8249.
  14. ^ Wright, Robert J.; Phillips, Andrew D.; Allen, Thomas L.; Fink, William H.; Power, Philip P. (2003-01-25). "Synthesis and Characterization of the Monomeric Imides Ar'MNAr' ' (M = Ga or In; Ar' or Ar' ' = Terphenyl Ligands) with Two-Coordinate Gallium and Indium". Journal of the American Chemical Society. 125 (7): 1694–1695. doi:10.1021/ja029422u. ISSN 0002-7863. PMID 12580583.
  15. ^ Hardman, Cui, Roesky, Fink, Power, Philip P., William H., Herbert W., Chunming, Ned J. (28 May 2001). <2172::AID-ANIE2172>3.0.CO;2-Y "Stable, Monomeric Imides of Aluminum and Gallium: Synthesis and Characterization of [{HC(MeCDippN)2}MN-2,6-Trip2C6H3] (M=Al or Ga; Dipp=2,6-iPr2C6H3; Trip=2,4,6-iPr3C6H2)". Angew. Chem. Int. Ed. (40): 2172–2174. doi:10.1002/1521-3773(20010601)40:11<2172::AID-ANIE2172>3.0.CO;2-Y.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  16. ^ Wright, Phillips, Allen, Fink, Power, Robert J., Andrew D., Thomas L., William H., Philip P. (January 25, 2003). "Synthesis and Characterization of the Monomeric Imides Ar'MNAr' ' (M = Ga or In; Ar' or Ar' ' = Terphenyl Ligands) with Two-Coordinate Gallium and Indium". J. Am. Chem. Soc. 125 (7): 1694–1695. doi:10.1021/ja029422u. PMID 12580583.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ^ "Isolable Phospha- and Arsaalumenes". J. Am. Chem. Soc. 143 (11): 4106–4111. March 10, 2021. doi:10.1021/jacs.1c00204.
  18. ^ Zhu, Hongping; Chai, Jianfang; Chandrasekhar, Vadapalli; Roesky, Herbert W.; Magull, Jörg; Vidovic, Denis; Schmidt, Hans-Georg; Noltemeyer, Mathias; Power, Philip P.; Merrill, William A. (2004-08-01). "Two Types of Intramolecular Addition of an Al−N Multiple-Bonded Monomer LAlNAr' Arising from the Reaction of LAl with N 3 Ar' (L = HC[(CMe)(NAr)] 2 , Ar' = 2,6-Ar 2 C 6 H 3 , Ar = 2,6- i Pr 2 C 6 H 3 )". Journal of the American Chemical Society. 126 (31): 9472–9473. doi:10.1021/ja0475712. ISSN 0002-7863. PMID 15291514.
  19. ^ Fischer, Malte; Nees, Samuel; Kupfer, Thomas; Goettel, James T.; Braunschweig, Holger; Hering-Junghans, Christian (2021-03-24). "Isolable Phospha- and Arsaalumenes". Journal of the American Chemical Society. 143 (11): 4106–4111. doi:10.1021/jacs.1c00204. ISSN 0002-7863. PMID 33691065. S2CID 232191822.
  20. ^ a b Helling, Christoph; Wölper, Christoph; Schulz, Stephan (2018-04-18). "Synthesis of a Gallaarsene {HC[C(Me)N-2,6- i -Pr 2 -C 6 H 3 ] 2 }GaAsCp* Containing a Ga═As Double Bond". Journal of the American Chemical Society. 140 (15): 5053–5056. doi:10.1021/jacs.8b02447. ISSN 0002-7863. PMID 29537831.
  21. ^ a b c Ganesamoorthy, Chelladurai; Helling, Christoph; Wölper, Christoph; Frank, Walter; Bill, Eckhard; Cutsail, George E.; Schulz, Stephan (2018-01-08). "From stable Sb- and Bi-centered radicals to a compound with a Ga=Sb double bond". Nature Communications. 9 (1): 87. Bibcode:2018NatCo...9...87G. doi:10.1038/s41467-017-02581-2. ISSN 2041-1723. PMC 5758792. PMID 29311607.
  22. ^ a b Wilson, Daniel W. N.; Feld, Joey; Goicoechea, Jose M. (2020-09-09). "A Phosphanyl‐Phosphagallene that Functions as a Frustrated Lewis Pair". Angewandte Chemie International Edition. 59 (47): 20914–20918. doi:10.1002/anie.202008207. ISSN 1433-7851. PMC 7693089. PMID 32615007.
  23. ^ a b c d Price, Amy N.; Nichol, Gary S.; Cowley, Michael J. (2017-07-19). "Phosphaborenes: Accessible Reagents for the Synthesis of C−C/P−B Isosteres". Angewandte Chemie. 129 (33): 10085–10089. Bibcode:2017AngCh.12910085P. doi:10.1002/ange.201705050. ISSN 0044-8249.
  24. ^ a b c Borys, Andryj M.; Rice, Ella F.; Nichol, Gary S.; Cowley, Michael J. (2021-09-08). "The Phospha-Bora-Wittig Reaction". Journal of the American Chemical Society. 143 (35): 14065–14070. doi:10.1021/jacs.1c06228. ISSN 0002-7863. PMC 8431359. PMID 34437805.
  25. ^ a b Marinetti, Angela; Mathey, François (October 1988). "A Novel Entry to the PC-Double Bond: the"Phospha-Wittig" Reaction". Angewandte Chemie International Edition in English. 27 (10): 1382–1384. doi:10.1002/anie.198813821. ISSN 0570-0833.
  26. ^ a b Li, Jianfeng; Li, Xiaofei; Huang, Wen; Hu, Hongfan; Zhang, Jianying; Cui, Chunming (2012-11-05). "Synthesis, Structure, and Reactivity of a Monomeric Iminoalane". Chemistry - A European Journal. 18 (48): 15263–15266. doi:10.1002/chem.201203298. ISSN 0947-6539. PMID 23129126.
  27. ^ Wilson, Daniel W. N.; Feld, Joey; Goicoechea, Jose M. (2020-09-09). "A Phosphanyl‐Phosphagallene that Functions as a Frustrated Lewis Pair". Angewandte Chemie. 132 (47): 21100–21104. doi:10.1002/ange.202008207. ISSN 0044-8249.
  28. ^ a b c Price, Amy N.; Cowley, Michael J. (2016-03-15). "Base-Stabilized Phosphinidene Boranes by Silylium-Ion Abstraction". Chemistry - A European Journal. 22 (18): 6248–6252. doi:10.1002/chem.201600836. ISSN 0947-6539. PMID 26918876.
  29. ^ Cowley, Alan H. (March 1987). "Multiple Bonding Involving Phosphorus; Some Recent Developments". Phosphorus and Sulfur and the Related Elements. 30 (1–2): 129–133. doi:10.1080/03086648708080539. ISSN 0308-664X.
  30. ^ Weber, Lothar (1992-12-01). "The chemistry of diphosphenes and their heavy congeners: synthesis, structure, and reactivity". Chemical Reviews. 92 (8): 1839–1906. doi:10.1021/cr00016a008. ISSN 0009-2665.
  31. ^ Sasamori, Takahiro; Tokitoh, Norihiro (2013-09-15). "A New Family of Multiple-Bond Compounds between Heavier Group 14 Elements". Bulletin of the Chemical Society of Japan. 86 (9): 1005–1021. doi:10.1246/bcsj.20130134. ISSN 0009-2673.
  32. ^ Yadav, Sandeep; Saha, Sumana; Sen, Sakya S. (March 2016). "ChemInform Abstract: Compounds with Low-Valent p-Block Elements for Small Molecule Activation and Catalysis". ChemInform. 47 (14). doi:10.1002/chin.201614233. ISSN 0931-7597.
  33. ^ Stephan, Douglas W. (2016-12-09). "The broadening reach of frustrated Lewis pair chemistry". Science. 354 (6317): aaf7229. doi:10.1126/science.aaf7229. ISSN 0036-8075. PMID 27940818. S2CID 45721140.
  34. ^ Hanusch, Franziska; Groll, Lisa; Inoue, Shigeyoshi (2021). "Recent advances of group 14 dimetallenes and dimetallynes in bond activation and catalysis". Chemical Science. 12 (6): 2001–2015. doi:10.1039/d0sc03192e. ISSN 2041-6520. PMC 8179309. PMID 34163962.
  35. ^ Weetman, Catherine (2020-11-19). "Main Group Multiple Bonds for Bond Activations and Catalysis". Chemistry – A European Journal. 27 (6): 1941–1954. doi:10.1002/chem.202002939. ISSN 0947-6539. PMC 7894548. PMID 32757381.
  36. ^ Wells, R. D.; Gladfelter, W. L. (1997-03-18). "Pathways to Nanocrystalline III-V (13-15) Compound Semiconductors". Journal of Cluster Science. Fort Belvoir, VA. doi:10.1023/A:1022684024708.
  37. ^ Malik, Afzaal, O’Brien*, Mohammad Azad, Mohammad, Paul (2010-05-19). "Precursor Chemistry for Main Group Elements in Semiconducting Materials". Chem. Rev. 110 (7): 4417–4446. doi:10.1021/cr900406f. PMID 20481563.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  38. ^ Davy, Randall D.; Jaffrey, Kent L. (September 1994). "Aluminum-Nitrogen Multiple Bonds in Small AlNH Molecules: Structures and Vibrational Frequencies of AlNH2, AlNH3, and AlNH4". The Journal of Physical Chemistry. 98 (36): 8930–8936. doi:10.1021/j100087a019. ISSN 0022-3654.
  39. ^ Davy, R. D.; Schaefer III, H. F. (2010-08-03). "ChemInform Abstract: Aluminum-Phosphorus Compounds with Low Coordination Numbers: Structures, Energies, and Vibrational Frequencies of the AlPH2, AlPH3, and AlPH4 Isomers and the H3Al-PH3 Adduct". ChemInform. 28 (28): no. doi:10.1002/chin.199728002. ISSN 0931-7597.
  40. ^ Himmel, Hans-Jörg; Downs, Anthony J.; Green, Jennifer C.; Greene, Tim M. (2001). "Compounds featuring a bond between a Group 13 (M) and a Group 15 element (N or P) and with the formulae HmMNHn and HmMPHn: structural aspects and bonding". Journal of the Chemical Society, Dalton Transactions (5): 535–545. doi:10.1039/b008724f. ISSN 1472-7773.
  41. ^ Himmel, Hans-Jörg; Schnöckel, Hansgeorg (2002-05-17). <2397::aid-chem2397>3.0.co;2-1 "Heats of Hydrogenation of Compounds Featuring Main Group Elements and with the Potential for Multiply Bonding". Chemistry - A European Journal. 8 (10): 2397–2705. doi:10.1002/1521-3765(20020517)8:10<2397::aid-chem2397>3.0.co;2-1. ISSN 0947-6539. PMID 12012422.