Short Si Research Articles

Analysis of Social Values and Characteristics in the Short Story Tupai Si Never Give Up Written SDN 13 Kolo Kota Bima

This study aims to examine the social values and characteristics contained in the short story 'Tupai Si Pantang Surrender' written by SDN 13 KOLO BIMA. The theory used is the theory of humanism put forward by Abraham Maslow with a sociology of literature approach. The method used in this research is a descriptive method with a qualitative research form. The subject of this research is the short story Tupai Si Unyielding' which was written by SDN 13 KOLO BIMA. The research data is in the form of paragraph excerpts and sentence fragments that contain elements of social values. The results of the study show that the social values contained are, 1) unyielding attitude, 2) compassion, 3) respect not demeaning, 4) persistence and hard work produce results according to what we use, 5) struggle, 6) admiration, 7) Regret. This study delves into the analysis of social values and characteristics embedded in the short story titled "Tupai Si Never Give Up," authored by SDN 13 Kolo Kota Bima. The research aims to uncover the narrative's underlying themes, socio-cultural reflections, and character dynamics. Employing a qualitative approach, the analysis focuses on the portrayal of social values such as perseverance, resilience, and community bonds, as well as the depiction of various characteristics exhibited by the story's protagonists. Through a close examination of the narrative elements, the study seeks to contribute to a deeper understanding of the cultural and social nuances presented in the short story, shedding light on the author's intent and the broader societal context in which the narrative unfolds.

Crystal structure and DFT calculations of Cp2NbH(SiIMe2)(SiFMe2): an asymmetric bis(silyl) niobocene hydride complex.

An asymmetric bis(silyl) niobocene hydride complex, namely, bis(η5-cyclopentadienyl)(fluorodimethylsilyl)hydrido(iododimethylsilyl)niobium, [Nb(C5H5)2(C2H6FSi)(C2H6ISi)H] or Cp2NbH(SiIMe2)(SiFMe2), has been studied to determine the effect of the silyl ligand on the position of the hydride attached to the Nb atom. It has been shown that when a Group 17 atom is substituted onto one of the silyl ligands, there is a greater interaction between the hydride and this ligand, as demonstrated by a shorter Si...H distance. In the present work, we have investigated the effect when the silyl ligands are substituted by different Group 17 atoms. We present here the structure and DFT calculations of Cp2NbH(SiIMe2)(SiFMe2), showing that the position of the hydride is located between the two silyl ligands. The results from our investigation show that the hydride is closer to the silyl ligand that is substituted by fluorine.

Hybrid Bicyclo[1.1.0]butanes [(R4Si3)CH2] and [(R4Si2Ge)CH2] (R = SiMetBu2): Synthesis and Thermal Isomerization to Alkyl-Substituted Cyclopropenes [R3Si3]CH2R and [R3Si2Ge]CH2R

Hybrid bicyclo[1.1.0]butanes comprised of different group 14 elements, namely, 1,2,3-trisilabicyclo[1.1.0]butane and 1,3-disila-2-germabicyclo[1.1.0]butane, were readily prepared by the reductive dichlorination of 1,3-dichlorocyclobutane precursors. Both compounds feature exceptionally short bridging Si–Si bonds and practically planar geometry around the bridging Si atoms, thus representing a novel structural motif in the chemistry of the heavy analogues of bicyclo[1.1.0]butanes. These peculiar structures were explained by the steric interaction between the substituents at the bridging and bridgehead positions. Thermolysis of the title bicyclo[1.1.0]butanes in toluene at 130 °C resulted in their isomerization to the alkyl-substituted cyclopropene analogues. The mechanism of this isomerization was revealed in detail on the basis of deuterium-labeled experiments, kinetic investigations, trapping experiments, and computational studies to establish the nature of the key intermediate of the whole isomerization process.

Diverse structural and electronic properties of carbon-substituted armchair silicene nanoribbons: A first-principles study

The structural and electronic properties of the armchair silicene nanoribbons (ASiNRs) under various C substitutions are investigated using the first-principles calculations. The C substitution-diversified structural and electronic properties are fully identified by the developed first-principles quantities, including the formation energies, phonon calculations, optimal structural parameters, orbital- and atom-projected density of states, and direction-projected spatial charge density distributions. The C substitutions at various adatom concentrations and distributions form the typical C substitution configurations of the single C, ortho-2C, meta-2C, para-2C, and 100% C, whereas the lower buckling height is found at the higher concentrations that become the flat 1D structure at 100% C substitution. The reshaped bandgaps are larger under shorter Si–C bond lengths. The largest opened bandgap of 2.37 eV is found at the highest adatom concentration of the 100% C configuration. The C substitutions generate the quasi σ bonds of the Si-(3s, 3p x , and 3p y ) and C-(2s, 2p x , and 2p y ) orbitals and the quasi π bonds of the Si-3p z and C-2p z orbitals, in which the quasi π orbitals create the long-range quasi π bands that determine the reshaped bandgaps. The quasi σ and π orbitals are hybridized at the middle valence energies that only separate at the deeper valence energies. The weak separation of the σ and π orbitals is responsible for the hybridization mechanism of the mixed sp 2 /sp 3 quasi in the C-substituted systems. The diverse electronic properties of the C-substituted ASiNRs will be very compatible with electronic and optoelectronic applications.

Plastic deformation induced microstructure transition in nano-fibrous Al-Si eutectics

Indentation plastic zone of Al-20 wt% Si laser rapid solidified (LRS) alloy with nanoscale, fibrous, fully eutectic microstructure is characterized using a combination of atomic force microscopy (AFM), scanning electron microscopy (SEM) and scanning/transmission electron microscopy (S/TEM). In contrast to cracking around the indents in the as-cast Al-Si alloy, the LRS nano-fibrous eutectic microstructure demonstrated higher strength, strain-hardening, and uniformly distributed plasticity around indents with no cracks. A transition in morphology from long nano-fibrous Si to short nano-fibrous Si is observed underneath the indent in LRS eutectics. The mechanism for this morphological evolution with increasing plastic strain is postulated to involve three stages of the deformation process: First, the formation of closely-spaced dislocation arrays in the nano-channels of Al matrix confined by Si fibers. Second, fiber segmentation when the stress field of the dislocation array exceeds the critical stress for fracture in Si nano-fibers. Third, recovery of dislocation substructures and sub-grain formation in Al leading to a rotation of fractured Si segments. The final microstructure consisted of short Si nano-fibers along triple junctions of the subgrains in Al. The implication of this unusual microstructure evolution with increasing plastic strain on the plastic co-deformation in high-strength LRS nano-eutectic microstructures was discussed in this report.

Si⋯O proximity in imidosilanes – absence of orbital interactions

Abstract New N-silylated phthalimides, succinimides, and 1,8-napthalimides were synthesised by reactions of the alkali imides with chlorosilanes in THF. Six different mono-, di-, tri- and tetra-iminosilanes of the type (CH3)4–n Si(imide) n were obtained and the products analysed with 1H, 13C, 29Si NMR, and Raman spectroscopy. The molecular structures of four imidosilanes have been determined by single-crystal X-ray diffraction. A characteristic structural feature of the compounds is the fact that all intramolecular Si⋯O distances are significantly below the sum of the van-der-Waals radii of silicon and oxygen of 3.62 Å. Experimentally found values for Si⋯O distances range from 2.813 to 3.030 Å. However, there are no significant orbital interactions between silicon and oxygen atoms, as shown by quantum chemical analysis with AIM and NBO methods. The short Si⋯O distances in these molecules are caused by the geometry of the rigid imide group bound to the silicon atom, and there is no evidence for an increase of the coordination number of the Si atoms.

The hierarchy of ab initio and DFT methods for describing an intramolecular non-covalent SiN contact in the silicon compounds using electron diffraction geometries.

In the series of silatranes XSi(OCH2CH2)3N, 1 (X = Me, 1a; H, 1b; F, 1c) with the known gas electron diffraction (GED) structures, the problematic geometry of 1-methylsilatrane 1a has been revised. In particular, the new value of the SiN distance (dSiN) in 1a turned out to be ∼0.06 Å longer than the generally accepted one. This dSiN resolves the long-standing contradiction between the data of the structural and spectral experiments regarding the sensitivity of 1 to the medium effect. We also performed the ab initio and DFT study of the combined series of silatranes 1a-c, silylalkylamines H3Si(CH2)3NMe2 (2a) and F3SiCH2NMe2 (2b), silylhydrazines F3SiN(Me)NMe2 (2c) and F3SiN(SiMe3)NMe2 (2d), and silyloxyamines ClH2SiONMe2 (2e,f), (F3C)F2SiONMe2 (2g,h) and F3SiONMe2 (2i), in which the GED dSiN values are in a wide range of 2-3 Å. None of the involved quantum chemical methods has succeeded in reproducing all the experimental gas-phase dSiN values in 1a-c, 2a-i with an acceptable accuracy (0.01-0.03 Å). The problems of the used methods, primarily CCSD with the Pople basis sets, are caused by four molecules with the geminal SiNN and SiON fragments (2d,f-i) and dSiN < 2.3 Å. A reasonable hierarchy of computationally accessible theory levels for studying the physicochemical manifestation of the non-covalent intramolecular SiN interactions can be constructed only at dSiN > 2.3 Å: MP2 < PBE0 ∼ B3PW91 ∼ SCS-MP2 < CCSD < CCSD(T).

Synthesis, in-situ membrane preparation, and good gas permselectivity of insoluble poly(substituted acetylene)s loosely cross-linked with short and soft siloxane and silanol linkages

Insoluble but membrane-formable poly(substituted acetylene)s loosely cross-linked by short and soft Si–O–Si and SiOH---(OH)Si linkages have been synthesized from the corresponding monomers having one or two SiOH groups. These monomers have been polymerized in homogeneous systems to produce homogeneous polymer solutions in toluene. The resulting solutions were cast on polytetrafuluoroethylene sheets followed by evaporation of the solvent to give tough and flexible membranes which were completely insoluble. The membranes showed good oxygen and carbon oxide permselectivity and their plots in PO2 vs PO2/PN2 graph exceeded the 1991 Robeson's upper bound and very close to the 2008 Robeson's upper bound. The excellent selectivity are caused by enhancement of diffusion selectivity by the soft network structure which can create small pores (i.e., ultramicro pores) based on the short linkages. No drop in permeability may be due to the soft Si–O–Si and SiOH---(OH)Si linkages. In addition no change in PO2 and PO2/PN2 by aging was observed.

Lithiation-Induced Structural Rearrangement and Stress Change in SiCO-Derived Porous Carbon: A First-Principles Study

Silicon oxycarbide (SiCO)-derived porous carbon is a promising anode material for high-power lithium-ion batteries with large reversible capacity and high rate performance. In this work, porous carbon compounds with various morphologies are successfully reproduced by simulating the etching process of SiCO and then lithiation-induced structural rearrangement and stress change in porous carbon are investigated using first-principles calculations. Upon insertion of lithium, Si–C/O mixed-bond units are destroyed with breaking of Si–O bonds, the lithium atoms prefer to form bonds with oxygen, and the pores are gradually filled with the Li–O complex. The negative stress of the lithiated system indicates local compression of Si–C/O units, which is also demonstrated by the shorter Si–O bonds and enhanced bulk modulus. The local compression is related to constraint of the carbon network that act as a buffering structure to limit volume expansion during lithiation, and the increase and decrease in normal stress are related to the stretching and breaking of the carbon network. Moreover, it is revealed that the lithium content that corresponds to the maximum stress can be used to estimate the specific capacity of the system. Our analysis of the lithiation process provides a conceptual foundation for future design of porous carbon-based anode materials.

X-ray absorption spectroscopy study on SiC-side interface structure of SiO2–SiC formed by thermal oxidation in dry oxygen

Extended X-ray absorption fine structure (EXAFS) spectroscopy is demonstrated to measure the fine atomic structure of SiO2–SiC interfaces. The SiC-side of the interface can be measured by fabricating thin SiO2 films and using SiC-selective EXAFS measurements. Fourier transforms of the oscillations of the EXAFS spectra correspond to radial-structure functions and reveal a new peak of the first nearest neighbor of Si for m-face SiC, which does not appear in measurements of the Si-face. This finding suggests that the m-face interface could include a structure with shorter Si–C distances. Numerical calculations provide additional support for this finding.

Silicon Promotes Growth of Brassica napus L. and Delays Leaf Senescence Induced by Nitrogen Starvation.

Silicon (Si) is the second most abundant element in soil and has several beneficial effects, especially in plants subjected to stress conditions. However, the effect of Si in preventing nitrogen (N) starvation in plants is poorly documented. The aim of this work was to study the effect of a short Si supply duration (7 days) on growth, N uptake, photosynthetic activity, and leaf senescence progression in rapeseed subjected (or not) to N starvation. Our results showed that after 1 week of Si supply, Si improves biomass and increases N uptake and root expression of a nitrate transporter gene. After 12 days of N starvation, compared to -Si plants, mature leaf from +Si plants showed a high chlorophyll content, a maintain of net photosynthetic activity, a decrease of oxidative stress markers [hydrogen peroxide (H2O2) and malondialdehyde (MDA)] and a significant delay in senescence. When N-deprived plants were resupplied with N, a greening again associated with an increase of photosynthetic activity was observed in mature leaves of plants pretreated with Si. Moreover, during the duration of N resupply, an increase of N uptake and nitrate transporter gene expression were observed in plants pretreated with Si. In conclusion, this study has shown a beneficial role of Si to alleviate damage associated with N starvation and more especially its role in delaying of leaf senescence.

Design of compact surface optical coupler based on vertically curved silicon waveguide for high-numerical-aperture single-mode optical fiber

A surface optical coupler based on a vertically curved Si waveguide was designed for coupling with high-numerical aperture single-mode optical fibers with a mode-field diameter of 5 µm. This coupler has a quite small device size, with a height of approximately 12 µm, achieved by introducing an effective spot-size converter configured with the combination of an extremely short Si exponential-inverse taper and a dome-structured SiO2 lens formed on the coupler top. The designed coupler shows high-efficiency optical coupling, with a loss of 0.8 dB for TE polarized light, as well as broad-band coupling with a 0.5-dB-loss band of 420 nm.

A Fairly Stable Crystalline Silanone

AbstractSilanones 2 substituted by bulky amino‐ and phosphonium ylide substituents have been synthesized and isolated in crystalline form. Thanks to the steric protection and the strong electron‐donating ability of the substituents, silanones 2 are persistent and only slowly dimerizes at room temperature (t1/2=0.5 or 5 h). Structural and theoretical analysis of 2 indicate a short Si=O bond (1.533 Å) and an enhanced polarization toward the O atom compared to Me2Si=O owing to the strong π‐electron donation from the phosphonium ylide substituent.

A Fairly Stable Crystalline Silanone.

Silanones 2 substituted by bulky amino- and phosphonium ylide substituents have been synthesized and isolated in crystalline form. Thanks to the steric protection and the strong electron-donating ability of the substituents, silanones 2 are persistent and only slowly dimerizes at room temperature (t1/2 =0.5 or 5 h). Structural and theoretical analysis of 2 indicate a short Si=O bond (1.533 Å) and an enhanced polarization toward the O atom compared to Me2 Si=O owing to the strong π-electron donation from the phosphonium ylide substituent.

Highly efficient hydrogen production using p-Si wire arrays and NiMoZn heterojunction photocathodes

Highly efficient photoelectrochemical (PEC) hydrogen production is achieved using p-Si wire arrays loaded with NiMoZn particles in aqueous sulfuric acid under simulated sunlight (AM 1.5G; 100mWcm−2). Vertically-aligned wire arrays are grown on planar Si wafers via a quick electroless etching process within 5min, leading to short Si wires of ∼4 μm and diameters of ∼0.2μm. Despite the short length of the wires, the reflectance of the arrays is<5% over the wavelength range of 400–800nm (the reflectance of planar Si is ∼40%) and the photocurrent density (Iph) is enhanced by ∼ 30% relative to planar Si. To further improve the PEC performance, ∼ 100nm NiMoZn particles are photoelectrochemically deposited onto the wires. The wire arrays with evenly distributed NiMoZn particles show a photocurrent onset potential (Eon) of ∼+0.27V vs. RHE and produce an Iph of ∼1.45mAcm−2 at 0V vs. RHE with a Faradaic efficiency of ∼ 100% for H2 evolution. This Iph value is ∼10-fold greater than that with the planar Si/NiMoZn samples. The excellent performance of the wire arrays and NiMoZn heterojunction is attributed to enhanced light absorption (decreased reflectance), facilitated charge transfer (radial-directional electron transfer), and NiMoZn-catalyzed hydrogen production.

Electrochemical Oxidation and Radical Cations of Structurally Non-rigid Hypervalent Silatranes: Theoretical and Experimental Studies.

Using 18 silatranes XSi(OCH2 CH2 )3 N (1) as examples, the potentials of electrochemical oxidation E0 of the hypervalent compounds of Si were calculated for the first time at the ab initio and DFT levels. The experimental peak potentials Ep (acetonitrile) show an excellent agreement (MAE=0.03) with the MP2//B3PW91 calculated E0 (C-PCM). Radical cations of 1 reveal a stretch isomerism of the N→Si dative bond. Localization of the spin density (SD) on the substituent X and the short (s) coordination contact Si⋅⋅⋅N (dSiN <2.13 Å) along with the high five-coordinate character of Si are typical for the first isomer 1+.(s) , whereas the second one, 1+.(l) , has a longer (l) Si⋅⋅⋅N distance (dSiN >3.0 Å), the four-coordinate Si and the SD localized on the silatrane nitrogen atom Ns . The vertical model of adiabatic ionization (1→1+.(s) or 1→1+.(l) ) was developed. It allows, in accordance with an original experimental test (electrooxidation of 1 in the presence of ferrocene), a reliable prediction of the most probable pathways of the silatrane oxidation. The reliable relationships of E0 (1) with the strength characteristics of the dative contact N→Si were revealed.

Donor‐Stabilized 1,3‐Disila‐2,4‐diazacyclobutadiene with a Nonbonded Si⋅⋅⋅Si Distance Compressed to a Si=Si Double Bond Length

AbstractA donor‐stabilized 1,3‐disila‐2,4‐diazacyclobutadiene presents an exceptionally short nonbonded Si⋅⋅⋅Si distance (2.23 Å), which is as short as that of Si=Si bonds (2.15–2.23 Å). Theoretical investigations indicate that there is no bond between the two silicon atoms, and that the unusual geometry can be related to a significant coulomb repulsion between the two ring nitrogen atoms. This chemical pressure phenomenon could provide an alternative and superior way of squeezing out van der Waals space in highly strained structures, as compared to the classical physical methods.

Donor‐Stabilized 1,3‐Disila‐2,4‐diazacyclobutadiene with a Nonbonded Si⋅⋅⋅Si Distance Compressed to a Si=Si Double Bond Length

A donor-stabilized 1,3-disila-2,4-diazacyclobutadiene presents an exceptionally short nonbonded Si⋅⋅⋅Si distance (2.23 Å), which is as short as that of Si=Si bonds (2.15-2.23 Å). Theoretical investigations indicate that there is no bond between the two silicon atoms, and that the unusual geometry can be related to a significant coulomb repulsion between the two ring nitrogen atoms. This chemical pressure phenomenon could provide an alternative and superior way of squeezing out van der Waals space in highly strained structures, as compared to the classical physical methods.

Atmospheric Pressure Selective Epitaxial Growth of Heavily in-situ Phosphorous-Doped Si(:C) Raised Sources and Drains

Raising the sources and drains regions of Fully Depleted Silicon-On-Insulator devices is mandatory in order to have enough material for silicidation and obtain low contact resistances. Doping was until the 28 nm technology node carried out using ion implantation. For a variety of reasons, in-situ doping is mandatory in future node transistors, however. We have thus focused on the in-situ phosphorous doping of the Si Raised Sources and Drains (RSDs) used in n-type devices. We have shown in [1] that reduced pressures (e.g. 20 Torr) were harmful in order to obtain at 750°C-800°C high P+ ions concentrations with reasonable Si:P Growth Rates (GR). With SiH2Cl2 + PH3 + HCl, we indeed saturated at [P+] around 1019 cm-3, with a surface poisoning by P atoms that drastically decreased the Si:P GR. Wanting to have a straightforward Si:P co-flow process instead of a more complex Cyclic Deposition/Etch process [2], we have thus studied the in-situ phosphorous doping of Si and Si1-yCy at Atmospheric Pressure (ATM) and in the 700°C – 800°C range. To that end, we have proceeded as follows. In order to gain access to the Si1-yCy:P layer thickness and confirm that layers were indeed single crystalline, we have grown {Si0.8Ge0.2 / Si1-yCy:P} stacks on Si(001) and measured them with X-Ray Reflectivity (which gives access to thickness) and X-Ray Diffraction (crystalline quality assessment), as shown in Figure 1. We have otherwise grown the very same Si1-yCy:P layers on slightly p-type substrates to have pn junctions and determine through four point probe measurements their sheet resistances. Resistivities and thus P+ ions concentrations were extracted by multiplying those by the Si1-yCy:P layer thicknesses (from XRR). We have plotted in Figure 2 the Si:P growth rate and [P+] at 750°C, ATM, this for increasing F(PH3)/F(SiH2Cl2) Mass-Flow Ratios (MFRs). When the SiH2Cl2 mass-flow was fixed, we had a significant increase of the Si:P GR (up to 13.3 nm/min.) and of [P+] (at most 7x1019 cm-3). We have tried to reach higher MFRs by reducing, for the highest PH3 1% in H2 flow deliverable in our tool, the SiH2Cl2 mass-flow. This led to (i) a Si:P growth rate decrease and (ii) to a slight [P+] decrease, instead of the increase hoped for. We have studied in Figure 3 the impact of growth temperature on the Si:P GR and on [P+] for the optimum point of Fig. 2. The activation energy associated with the Si:P growth rate increase with temperature in the 700°C-800°C range was equal to 53 kcal. mol.-1 (e.g. close to the Si-H bond strength), while [P+] was steady at 7x1019 cm-3. We have thus moved over to a PH3 5% in H2 bottle and quantified, at 700°C, ATM, the impact of the PH3 flow on the Si:P growth rate and n-type doping for fixed SiH2Cl2 and HCl mass-flows. We have in Figure 4 a sharp increase, a stabilization then a Si:P GR decrease as the PH3 flow increases, which might be due to surface poisoning. Such a behaviour is associated with a P+ ion concentration that sharply increases then reaches a plateau close to 1020 cm-3. We have used such a co-flow processes to thicken at 725°C, ATM the sources and drains regions of stacked Si nanowires with 50 nm of Si:P. The surface of those RSDs was slightly rough (as for Si:P layers on blanket substrates). Full selectivity versus SiO2 (Buried OXyde) and SiN internal spacers was achieved, however, as illustrated by the SEM images of Figure 5. Finally, we have studied the feasibility of adding SiCH6 to the gaseous mixture in order to have C atoms that would supress B diffusion (p+ pockets to control short channel effects in bulk nMOS transistors) and hopefully inject tensile strain in short Si channels (if the substitutional C content is high enough). Because of the rather high temperature (700°C), we were not able to obtain [Csubst.] above 0.55%, as shown by Figure 6 XRD profiles. We were otherwise faced with a Si1-yCy:P GR that decreased and a layer resistivity that increased as the SiCH6 mass-flow increased (competition between P and C atoms for incorporation in the lattice and electron mobility degradation because of the small size of the C atoms), as shown in Figure 7. The best trade-off was achieved for a F(SiCH6)/F(PH3) MFR close to unity. [1] J.M. Hartmann et al, J. Cryst. Growth 264 (2004) 36 and J. Cryst. Growth 310 (2008) 62. [2] J.M. Hartmann et al., Semicond. Sci. Technol. 28 (2013) 025017 and 025018. Figure 1

Role of N-donor groups on the stability of hydrazide based hypercoordinate silicon(IV) complexes: Theoretical and experimental perceptions

A triphenylphosphinimino donor group is illustrated as a ligand in pentacoordinate siliconium halide dichelates, [YSiL2]+X−, where L is the bidentate ligand –OC(R)NNPPh3)– (R=t-Bu-Ph or Ph), Y=Me, Ph, CH2Cl, CHCl2, Cl or Br, and X=Cl or Br. All the new complexes were characterized by NMR spectroscopy and elemental analysis. The remote substituent, the t-Bu-phenyl or phenyl group, imparts more pentacoordinate character, i.e. more ionization to the complexes, compared to the PhCH2 group. DFT calculations indicate that the central silicon atom, due to the more positive charge, demands greater electron density. As a result of this, shorter Si–O, Si–N and Si–Cl bonds were observed. Both theoretical and experimental analysis indicate that the phosphinimino ligand is a stronger donor than the previously studied dimethylamino and isopropylidenimino ligands, causing all of the complexes to be pentacoordinate siliconium-halide salts in solution. The hypercoordinate silicon dichelates undergo unique intermolecular chelate exchange reactions: (i) complete ligand transfer from the dichelates to PhSiCl3 by a ligand priority order and (ii) bidentate ligand interchange between the dichelates and a trimethylsilyl-hydrazide precursor. Thermolysis of some selected hypercoordinated silicon(IV) complexes containing a silicon–carbon σ-bond significantly undergo a two step decomposition, while other complexes with silicon–halogen σ-bonds follow three steps. The thermal decomposition strongly depends on the nature of the substituents directly attached to the central silicon atom.