Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Dec 26;61(51):20848-20859.
doi: 10.1021/acs.inorgchem.2c03186. Epub 2022 Nov 2.

σ-GeH and Germyl Cationic Pt(II) Complexes

Carlos J Laglera-Gándara  1 , Pablo Ríos  1 , Francisco José Fernández-de-Córdova  1 , Marina Barturen  1 , Israel Fernández  2 , Salvador Conejero  1
Affiliations

σ-GeH and Germyl Cationic Pt(II) Complexes

Carlos J Laglera-Gándara et al. Inorg Chem. .

Abstract

The low electron count Pt(II) complexes [Pt(NHC')(NHC)][BArF] (where NHC is a N-heterocyclic carbene ligand and NHC' its metalated form) react with tertiary hydrogermanes HGeR3 at room temperature to generate the 14-electron platinum(II) germyl derivatives [Pt(GeR3)(NHC)2][BArF]. Low-temperature NMR studies allowed us to detect and characterize spectroscopically some of the σ-GeH intermediates [Pt(η2-HGeR3)(NHC')(NHC)][BArF] that evolve into the platinum-germyl species. One of these compounds has been characterized by X-ray diffraction studies, and the interaction of the H-Ge bond with the platinum center has been analyzed in detail by computational methods, which suggest that the main contribution is the donation of the H-Ge to a σ*(Pt-C) orbital, but backdonation from the platinum to the σ*(Ge-H) orbital is significant. Primary and secondary hydrogermanes also produce the corresponding platinum-germyl complexes, a result that contrasts with the reactivity observed with primary silanes, in which carbon-silicon bond-forming reactions have been reported. According to density functional theory calculations, the formation of Pt-Ge/C-H bonds is both kinetically and thermodynamically preferred over the competitive reaction pathway leading to Pt-H/C-Ge bonds.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing financial interest.

Figures

Scheme 1
Scheme 1. Reactions of Cyclometalated Complex [Pt(ItBuiPr′)(ItBuiPr)][BArF] with Hydrosilanes (A) and Hydroboranes (B)
Figure 1
Figure 1
Thermal ellipsoid depiction of the cationic fragments of complexes 2.1a, 2.1b, 2.2b, and 2.3b (hydrogens omitted for clarity). Thermal ellipsoids at 30% probability. Selected bond distances (Å) and angles (°): 2.1a: Pt1-Ge1, 2.3938(6); Pt1-C1, 2.029(6); Pt1-C9, 2.020(6); and C1-Pt1-C9, 172.1(2). 2.1b: Pt1-Ge1, 2.3953(5); Pt1-C1, 2.031(3); Pt1-C9, 2.028(3); and C1-Pt1-C9, 169.0(1). 2.2b: Pt1-Ge1, 2.3881(5); Pt1-C1, 2.015(3); Pt1-C11, 2.027(3); and C1-Pt1-C11, 167.5(1). 2.3b: Pt1-Ge1, 2.4075(6); Pt1-C1, 2.029(4); Pt1-C13, 2.041(4); and C1-Pt1-C9, 172.8(2).
Scheme 2
Scheme 2. Reaction of Complexes [Pt(NHC′)(NHC)][BArF] (1.1–1.3) with Tertiary Hydrogermanes
Scheme 3
Scheme 3. Reactions of Complexes 1.2 (A) and 1.4 (B) with Primary and Secondary Hydrogermanes
Scheme 4
Scheme 4. Reaction of Cyclometalated Complex 1.3 and Hydride 4 with Primary and Secondary Hydrogermanes
Figure 2
Figure 2
Thermal ellipsoid depiction of the cationic fragment of complex 2.4d (hydrogen, except H1, and some carbon atoms omitted for clarity). Thermal ellipsoids at 30% probability. Selected bond distances (Å) and angles (°): Pt1-Ge1, 2.36248(6); Ge1-H1, 1.45(3); Pt1-C1, 2.025(4); Pt1-C24, 2.038(4); and C1-Pt1-C24, 167.1(2).
Scheme 5
Scheme 5. Low-Temperature NMR Experiments between Complex 1.2 and Hydrogermanes
Figure 3
Figure 3
Thermal ellipsoid (left) and DFT-calculated (right) representations of 1.2·HGeEt3. Thermal ellipsoids are set to 30% probability. BArF anion and hydrogen atoms (except H27) are omitted for clarity. Selected bond distances [Å] and angles [°]: Experimental [Theoretical]: Pt2-C20, 2.041(3) [2.062]; Pt2-C35, 2.012(2) [2.024]; Pt2-C47, 2.089(3) [2.102]; Pt2-H27, 1.41(4) [1.695]; Ge2-H27, 1.78(4) [1.786]; Pt2···Ge2, 2.6468(8) [2.659]; Pt2-H27-Ge2, 111(2) [99.6]; and C47-Pt2-H27, 172.1 [168.4], C20-Pt2-C35, 167.8 (1) [167.7].
Figure 4
Figure 4
Deformation densities and associated molecular orbitals of the most important orbital interactions, ΔEorb(1) and ΔEorb(2), in complex 1.2·HGeEt3. The color code used to represent the flow of charge is red→blue. All data were computed at the ZORA–BP86-D3/TZ2P//RI-BP86-D3/def2-TZVPP level. Results from EDA-NOCV (in kcal mol–1): ΔEPauli = 185.4; ΔEelstat = −137.4; ΔEorb = −78.1; ΔEdisp = −26.2; and ΔEint = −56.3 (see the Supporting Information for a description of each term).
Figure 5
Figure 5
Computed Gibbs energy profile in dichloromethane for the C–H coupling pathway (NHCs in cis) upon reaction between 1.2 and nBuGeH3. Gibbs energies computed at 298 K are given in kcal mol–1. The Gibbs energy of 1.2 + nBuGeH3 has been taken as zero-energy.
Figure 6
Figure 6
Computed Gibbs energy profile in dichloromethane for the C–Ge coupling pathway (NHCs in cis) upon reaction between 1.2 and nBuGeH3. Gibbs energies computed at 298 K are given in kcal mol–1. The Gibbs energy of 1.2 + nBuGeH3 has been taken as zero-energy.
Figure 7
Figure 7
Computed Gibbs energy profile in dichloromethane for the processes that might take place after C–Ge bond formation (NHCs in cis), namely, H2 extrusion (left) or C–Ge bond cleavage (right). Gibbs energies computed at 298 K are given in kcal mol–1. The Gibbs energy of 1.2 + nBuGeH3 has been taken as zero-energy.
Scheme 6
Scheme 6. Exchange Reactions of Complexes 2.1a,b and Hydrosilanes
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Whited M. T.; Taylor B. L. H. Metal/organosilicon complexes: structure, reactivity, and considerations for catalysis. Comments Inorg. Chem. 2020, 40, 217–276. 10.1080/02603594.2020.1737026. - DOI
    2. Corey J. Y. Reactions of hydrosilanes with transition metal complexes. Chem. Rev. 2016, 116, 11291–11435. 10.1021/acs.chemrev.5b00559. - DOI - PubMed
    3. Riddlestone I. M.; Abdalla J. A. B.; Aldridge S. Coordination and activation of E–H Bonds (E = B, Al, Ga) at transition metal centers. Adv. Organomet. Chem. 2015, 63, 1–38.
    4. Corey J. Y. Reactions of hydrosilanes with transition metal complexes and characterization of the products. Chem. Rev. 2011, 111, 863–1071. 10.1021/cr900359c. - DOI - PubMed
    5. Pandey K. K. Transition metal σ-borane complexes. Coord. Chem. Rev. 2009, 253, 37–55. 10.1016/j.ccr.2007.11.026. - DOI
    6. Alcaraz G.; Grellier M.; Sabo-Etienne S. Bis σ-bond dihydrogen and borane ruthenium complexes: bonding nature, catalytic applications, and reversible hydrogen release. Acc. Chem. Res. 2009, 42, 1640–1649. 10.1021/ar900091a. - DOI - PubMed
    7. Nikonov G. I. Recent advances in nonclassical interligand Si···H interactions. Adv. Organomet. Chem. 2005, 53, 217–309.
    8. Kubas G. J. Heterolytic splitting of H–H, Si–H, and other σ bonds on electrophilic metal centers. Adv. Inorg. Chem. 2004, 56, 127–177.
    1. Handzlik J.; Kochel A.; Szymańska-Buzar T. H–Ge bond activation by tungsten carbonyls: An experimental and theoretical study. Polyhedron 2012, 31, 622–637. 10.1016/j.poly.2011.10.040. - DOI
    2. Zyder M.; Szymańska-Buzar T. Activation of the Ge–H bond of Et3GeH in photochemical reaction with molybdenum(0) carbonyl complexes and hydrogermylation of norbornadiene. J. Organomet. Chem. 2009, 694, 2110–2113. 10.1016/j.jorganchem.2009.02.013. - DOI
    3. Sabo-Etienne S.; Hernandez M.; Chung G.; Chaudret B.; Castel A. Substitution reactions of coordinated dihydrogen by weakly coordinating ligands: preparation of RuH2(N2)2(PCy3)2 and RuH2(η2-H2)(HEPh3)(PCy3)2 (E = Si, Ge). New J. Chem. 1994, 18, 175–177.
    4. Lichtenberger D. L.; Rai-Chaudhuri A. Electronic structure factors of Ge–H bond activation by transition metals. Photoelectron spectra of [Mn(η5-C5H5)(CO)2(HGePh3)], [Mn(η5-C5H4Me)(CO)2(HGePh3)], and [Mn(η5-C5Me5)(CO)2(HGePh3)]. J. Chem. Soc., Dalton Trans. 1990, 2161–2166. 10.1039/DT9900002161. - DOI
    5. Garré F.; Colomer E.; Corriu R. J. P.; Vioux A. Stereochemistry of the insertion of manganese into Si–H and Ge–H Bonds. Complexes containing a two-electron, three-center Mn···H···Si (or Ge) interaction. Organometallics 1984, 3, 1272–1278. 10.1021/om00086a022. - DOI
    1. Smart K. A.; Mothes-Martin E.; Vendier L.; Perutz R. N.; Grellier M.; Sabo-Etienne S. A ruthenium dihydrogen germylene complex and the catalytic synthesis of digermoxane. Organometallics 2015, 34, 4158–4163. 10.1021/acs.organomet.5b00570. - DOI
    2. Vincent J. L.; Luo S.; Scott B. L.; Butcher R.; Unkefer C. J.; Burns C. J.; Kubas G. J.; Lledós A.; Maseras F.; Tomàs J. Oxidative addition of germanes and silanes, EH4-nPhn (E = Si, Ge; n = 0-3), to Mo(CO)(diphosphine)2. The first structurally characterized germane σ complex. Organometallics 2003, 22, 5307–5323. 10.1021/om030569j. - DOI

    3. For “agostic” (mono- and di-nuclear) complexes see:

    4. Takaya J.; Iwasawa N. Synthesis, structure, and reactivity of a mononuclear η2-(Ge–H)-palladium(0) complex bearing a PGeP-pincer-type germyl ligand: reactivity differences between silicon and germanium. Eur. J. Inorg. Chem. 2018, 2018, 5012–5018. 10.1002/ejic.201801257. - DOI
    5. Mobarok M. H.; McDonald R.; Ferguson M. J.; Cowie M. Germyl- and germylene-bridged complexes of Rh/Ir and subsequent chemistry of a bridging germylene group. Inorg. Chem. 2012, 51, 4020–4034. 10.1021/ic2021269. - DOI - PubMed
    6. Zyder M.; Kochel A.; Handzlik J.; Szymańska-Buzar T. Photochemical reaction of Mo(CO)6 with Et2GeH2: NMR and DFT studies of reaction products; crystal structure of a novel complex [{Mo(μ-η2-H-GeEt2)(CO)4}2]. Organometallics 2009, 28, 5857–5865. 10.1021/om900299k. - DOI
    7. Tanabe M.; Ishikawa N.; Osakada K. Preparation and structure of a new dipalladium complex with bridging diphenylgermyl ligands. Diverse reactivities of Pd(PCy3)2 and Pt(PCy3)2 toward Ph2GeH2. Organometallics 2006, 25, 796–798. 10.1021/om050981u. - DOI
    8. Braddock-Wilking J.; Corey J. Y.; White C.; Xu H.; Rath N. P. Reaction of diphenylgermane with (Ph3P)2Pt(η2-C2H4): generation of mono- and dinuclear complexes containing Pt–Ge bonds. X-ray crystal structure determination of [(Ph3P)Pt(μ-η2-H-GePh2)]2. Organometallics 2005, 24, 4113–4115. 10.1021/om050392o. - DOI
    1. Ríos P.; Martín-de la Calle R.; Vidossich P.; Fernández-de-Córdova F. J.; Lledós A.; Conejero S. Reversible carbon–boron bond formation at platinum centers through σ-BH complexes. Chem. Sci. 2021, 12, 1647–1655. 10.1039/D0SC05522K. - DOI - PMC - PubMed
    2. Ríos P.; Fouilloux H.; Díez J.; Vidossich P.; Lledós A.; Conejero S. σ-Silane platinum(II) complexes as intermediates in C–Si bond- coupling processes. Chem. - Eur. J. 2019, 25, 11346–11355. 10.1002/chem.201902226. - DOI - PubMed
    3. Ríos P.; Fouilloux H.; Vidossich P.; Díez J.; Lledós A.; Conejero S. Isolation of a cationic platinum(II) σ-silane complex. Angew. Chem., Int. Ed. 2018, 57, 3217–3221. 10.1002/anie.201712791. - DOI - PubMed
    4. Ríos P.; Díez J.; López-Serrano J.; Rodríguez A.; Conejero S. Cationic platinum(II) σ-SiH complexes in carbon dioxide hydrosilation. Chem. - Eur. J. 2016, 22, 16791–16795. 10.1002/chem.201603524. - DOI - PubMed
    5. Rivada-Wheelaghan O.; Roselló-Merino M.; Ortuño M. A.; Vidossich P.; Gutiérrez-Puebla E.; Lledós A.; Conejero S. Reactivity of coordinatively unsaturated bis(N-heterocyclic carbene) Pt(II) complexes toward H2. Crystal structure of a 14-electron Pt(II) hydride complex. Inorg. Chem. 2014, 53, 4257–4268. 10.1021/ic500705t. - DOI - PubMed
    6. Ríos P.; Fernández-de-Córdova F. J.; Borge J.; Curado N.; Lledós A.; Conejero S. Ligand effects in carbon-boron coupling processes mediated by σ-BH platinum complexes. Eur. J. Inorg. Chem. 2021, 2021, 3528–3539. 10.1002/ejic.202100428. - DOI

    1. See for example:

    2. Selmani A.; Schoetz M. D.; Queen A. E.; Schoenebeck F. Modularity in the Csp3 space–alkyl germanes as orthogonal molecular handles for chemoselective diversification. ACS Catal. 2022, 12, 4833–4839. 10.1021/acscatal.2c00852. - DOI
    3. Dahiya A.; Schoenebeck F. Direct C–H dehydrogenative germylation of terminal alkynes with hydrogermanes. Org. Lett. 2022, 24, 2728–2732. 10.1021/acs.orglett.2c00840. - DOI - PubMed
    4. Xu Q.-H.; Wei L.-P.; Xiao B. Alkyl-GeMe3: neutral metalloid radical precursors upon visible light photocatalysis. Angew. Chem., Int. Ed. 2022, 61, e202115592. - PubMed
    5. Luo Y.; Xu B.; Lv L.; Li Z. Copper-catalyzed three-component germyl peroxidation of alkenes. Org. Lett. 2022, 24, 2425–2430. 10.1021/acs.orglett.2c00698. - DOI - PubMed
    6. Su P.-F.; Wang K.; Peng X.; Pang X.; Guo P.; Shu X.-Z. Nickel-catalyzed reductive C–Ge coupling of aryl/alkenyl electrophiles with chlorogermanes. Angew. Chem., Int. Ed. 2021, 60, 26571–2657. 10.1002/anie.202112876. - DOI - PubMed
    7. Kojima K.; Uchida S.; Kinoshita H.; Miura K. Synthesis of polysubstituted germoles and benzogermoles using a substoichiometric amount of diisobutylaluminum hydride. Org. Lett. 2021, 23, 4598–4602. 10.1021/acs.orglett.1c01314. - DOI - PubMed
    8. Fricke C.; Schoenebeck F. Organogermanes as orthogonal coupling partners in synthesis and catalysis. Acc. Chem. Res. 2020, 53, 2715–2725. 10.1021/acs.accounts.0c00527. - DOI - PubMed
    9. Sherborne G. J.; Gevondian A. G.; Funes-Ardoiz I.; Dahiya A.; Fricke C.; Schoenebeck F. Modular and selective arylation of aryl germanes (C–GeEt3) over C–Bpin, C–SiR3 and halogens enabled by light-activated gold catalysis. Angew. Chem., Int. Ed. 2020, 59, 15543–15548. 10.1002/anie.202005066. - DOI - PMC - PubMed
    10. Liang H.; Ji Y.-X.; Wang R.-H.; Zhang Z.-H.; Zhang B. Visible-light-initiated manganese-catalyzed E-selective hydrosilylation and hydrogermylation of alkynes. Org. Lett. 2019, 21, 2750–2754. 10.1021/acs.orglett.9b00701. - DOI - PubMed
    11. Xue W.; Mao W.; Zhang L.; Oestreich M. Mechanistic dichotomy of magnesium- and zinc-based germanium nucleophiles in the C(sp3)–Ge cross-coupling with alkyl electrophiles. Angew. Chem., Int. Ed. 2019, 58, 6440–6443. 10.1002/anie.201901860. - DOI - PubMed
    12. Keess S.; Oestreich M. Access to fully alkylated germanes by B(C6F5)3-catalyzed transfer hydrogermylation of alkenes. Org. Lett. 2017, 19, 1898–1901. 10.1021/acs.orglett.7b00672. - DOI - PubMed