Ar Cl Research Articles

Comparative analysis of ArnCl2 (2 ≤ n ≤ 30) clusters taking into account molecular relaxation effects

AbstractCluster structures are discussed in a nonrigid analysis, using a modified minima search method based on stochastic processes and classical dynamics simulations. The relaxation process is taken into account considering the internal motion of the Cl2 molecule. Cluster structures are compared with previous works in which the Cl2 molecule is assumed to be rigid. The interactions are modeled using pair potentials: the Aziz and Lennard–Jones potentials for the ArAr interaction, a Morse potential for the ClCl interaction, and a fully spherical/anisotropic Morse–Spline–van der Waals (MSV) potential for the ArCl interaction. As expected, all calculated energies are lower than those obtained in a rigid approximation; one reason may be attributed to the nonrigid contributions of the internal motion of the Cl2 molecule. Finally, the growing processes in molecular clusters are discussed, and it is pointed out that the growing mechanism can be affected due to the nonrigid initial conditions of smaller clusters such as ArnCl2 (n ≤ 4 or 5), which are seeds for higher‐order clusters. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006

What's in a name? Noncovalent Ar–Cl·(H–Ar′)ninteractions and terminology based on structure and nature of the bonding

Interactions are named based on the interacting moieties and on the mechanism of their interaction. These approaches are independent. The former approach relies on the knowledge of structure alone and the latter requires additional knowledge about electronic structure. Knowledge about the nature of the bonding is additional knowledge; it serves to provide detail and this knowledge should not be used to exclude the naming of the interaction based on structure alone.

Coupling of arylamine with coordinated arylazopyrimidine in platinum(II) complexes. Single crystal X-ray structure, spectra and electrochemistry

2-(Arylazo)pyrimidine ( p-R-C 6H 4–N N–C 4H 3N 2, aapm, R = H (papm, 3a), Me (tapm, 3b), Cl (Clpapm, 3c)) are N, N′-chelating ligands. Platinum(II) complexes, Pt(aapm)Cl 2 ( 4) have been synthesized by the reaction of K 2PtCl 4 and aapm in MeCN–water under refluxing condition. The reaction of Pt(aapm)Cl 2 with ArNH 2 in MeCN has synthesized C–N coupled product, Pt(aapm-N–Ar)Cl ( 5– 10). The single crystal X-ray structure determination of one of the compounds has suggested the coupling of ArNH 2 at ortho-C–H of the pendant aryl part of aapm in the chelated complex. The stereochemistry and the bonding are described by 1H NMR data. The solution electronic spectra of Pt(aapm-N–Ar)Cl exhibit multiple transition at Vis–NIR region (500–1250 nm) which are absent in Pt(aapm)Cl 2. Cyclic voltammograms show two quasireversible azo reductions of Pt(aapm)Cl 2; Pt(aapm-N–Ar)Cl exhibit four successive redox couples, one of them (positive to SCE) is oxidative in nature and other (negative to SCE) are ligand reductions.

Etch Characteristics of Al2O3 in ICP and MERIE Plasma Etchers

The etch characteristics of films were investigated for magnetically enhanced reactive ion etching (MERIE) and inductively coupled plasma (ICP) etch systems as a function of bias power, source power, and gas chemistry. Compared to pure Ar sputtering, F-, Cl-, and Br-based plasma provided a significant chemical enhancement. Fluorine containing plasma produced higher etch rates compared to Cl and Br. The selectivity for over other semiconductor materials is low for all of the investigated two-gas mixtures. A polymerizing chemistry provides acceptable selectivity to Si, and was used for a patterning of an hard mask. These structures have been transferred into the Si wafer.

Molybdenum alkylidyne complexes that contain a 3,3′-di- t-butyl-5,5′,6,6′-tetramethyl-1,1′-biphenyl-2,2′-diolate ([Biphen] 2−) ligand

The reaction between K 2[Biphen] ([Biphen] 2−=3,3′-Di- t-butyl-5,5′,6,6′-tetramethyl-1,1′-Biphenyl-2,2′-diolate) and Mo(NAr Cl)(CH- t-Bu)(OTf) 2(dme) (Ar Cl=2,6-Cl 2C 6H 3) in the presence of ten equivalents of triethylamine gave Mo(NHAr Cl)(C- t-Bu)[Biphen] ( 4a) in 40–50% yield. Addition of K 2[ S-Biphen] to Mo(NAr Cl)(CHCMe 2Ph)(OTf) 2(THF) in THF led to the isolation of Mo(NHAr Cl)(CCMe 2Ph)[ S-Biphen] ( 4b) in ∼40% yield. An X-ray crystal study of 4b confirmed the proposed structure and also revealed that one ortho chloride approaches within 2.93 Å of the metal approximately trans to the alkylidyne ligand. Addition of one equivalent of H 2[Biphen] to Mo(CCH 2SiMe 3)[N( i-Pr)Ar″)] 3 (Ar″=3,5-dimethylphenyl) produced Mo(CCH 2SiMe 3)[Biphen][N( i-Pr)Ar″)] in situ, which when treated with one equivalent of 1-adamantanol gave a mixture of Mo(CCH 2SiMe 3)[Biphen](OAd) ( 9) and three equivalents of HN( i-Pr)Ar″, from which 9 could be isolated as a beige powder in 46% yield. An X-ray study of 9 confirmed that it is a pseudotetrahedral species in which the MoC bond length is 1.707(15) Å and the MoCC angle is 168.3(11)°. Addition of ten equivalents of 2-butyne or 3-hexyne to a pale yellow solution of 9 produced the molybdacyclobutadiene complexes Mo(C 3R 3)[Biphen](OAd) (R=Me or Et; 10a and 10b, respectively) in high yield. Both 10a and 10b decompose slowly in solution, even in the presence of added alkyne. An X-ray structure of the decomposition product of 10a revealed it to have the stoichiometry of 10a plus one additional equivalent of 2-butyne. The most unusual feature of the structure of this alkyne complex is a fusion of the C 3Me 3 portion of the metallacyclobutadiene ring to carbons in position 5 and 6 in the [Biphen] 2− backbone to create a σ allyl linkage . These results suggest that Mo biphenolate alkylidyne complexes are not likely to be stable under conditions where alkynes are metathesized.

Synthetic, structural, and mechanistic studies on the oxidative addition of aromatic chlorides to a palladium (N-heterocyclic carbene) complex: relevance to catalytic amination.

The oxidative addition products trans-[Pd(NHC)(2)(Ar)Cl] (NHC = cyclo-C[N(t)BuCH](2); Ar = Me-4-C(6)H(4), MeO-4-C(6)H(4), CO(2)Me-4-C(6)H(4)) have been isolated in good yields from the reactions of ArCl with the amination precatalyst [Pd(NHC)(2)] and structurally characterized. The former undergo reversible dissociation of one NHC ligand at elevated temperatures, and a value of 25.57 kcal mol(-1) has been determined for the Pd-NHC dissociation enthalpy in the case where Ar = Me-4-C(6)H(4). Detailed kinetic studies have established that the oxidative addition reactions proceed by a dissociative mechanism. Rate data for the oxidation addition of Me-4-C(6)H(4)Cl to [Pd(NHC)(2)] compared to that obtained for the [Pd(NHC)(2)]-catalyzed coupling of morpholine with 4-chlorotoluene are consistent with a rate-determining oxidative addition in the catalytic amination reaction. The relative rates of oxidative addition of the three aryl chlorides to [Pd(NHC)(2)] (CO(2)Me-4-C(6)H(4)Cl > Me-4-C(6)H(4)Cl > MeO-4-C(6)H(4)Cl) reflect the electronic nature of the substituents and also parallel observed trends in coupling efficiency for these aryl halides in aminations.

Effects of early postnatal ethanol intubation on GABAergic synaptic proteins

Fetal alcohol syndrome includes brain damage from aberrant synaptogenesis, altered cell–cell signaling and blunted plasticity in surviving neurons. Distortion of neurotrophic GABA signals by ethanol-mediated allosteric modulation of GABA A receptor (GABA AR) activity during brain maturation may play a role. In this regard, early postnatal binge-like ethanol treatment on postnatal days (PDs) 4–9 acutely inhibits whole cell GABA AR Cl − current and subsequently blunts GABA AR function in medial septum/diagonal band (MS/DB) neurons and cerebellar Purkinje cells [ Dev. Brain Res. 130 (2001) 25–40; Brain Res. 810 (1998) 100–113; Brain Res. 832 (1999) 124–135]. In light of these functional changes, we hypothesized that ethanol treatment also would decrease levels of proteins important for assembly of GABAergic synapses in maturing brain. To test this relationship, binge-like ethanol intubation was administered to rat pups on PDs 4–9 producing peak blood ethanol concentrations in the range of 302.5±6.3 mg/dl. GABAergic synaptic proteins were measured in brain tissue on PDs 13–14 when GABA AR currents in individual MS/DB neurons are reduced, but those of cerebellar Purkinje neurons are not yet altered [ Dev. Brain Res. 130 (2001) 25–40; Brain Res. 810 (1998) 100–113; Brain Res. 832 (1999) 124–135]. Surprisingly, ethanol did not decrease protein levels of GABA AR α1/β2 subunits, GAD 67 or gephyrin in MS/DB at this time when whole cell recordings indicate GABA AR function is impaired in acutely dissociated individual neurons. However, in cerebellum where ethanol treated Purkinje cell GABA AR function remains normal on PDs 13–14 [ Brain Res. 832 (1999) 124–135], reduced levels of several GABAergic synaptic proteins including: GAD 67, GABA AR α1 subunit, ClC-2 a voltage-gated Cl − channel, synaptotagmin a synaptic vesicle protein, and N-cadherin, a synapse associated cell adhesion molecule, were found. These results indicate that binge-like ethanol exposure differentially decreases GABAergic synaptic proteins in some brain areas in a pattern that does not parallel reductions in GABA AR function of individual neurons that survive this ethanol insult.

Characterization of ArnCl(−) clusters (n=2–15) using zero electron kinetic energy and partially discriminated threshold photodetachment spectroscopy

Ar n Cl − clusters have been investigated by anion zero electron kinetic energy (ZEKE) and partially discriminated threshold photodetachment spectroscopy. The experiments yield size-dependent electron affinities (EAs) and electronic state splittings for the X, I, and II states accessed by photodetachment. Cluster minimum energy structures have been determined from calculations based on a “simulated annealing” approach employing our recently presented Ar–Cl(−) pair potentials from anion ZEKE spectroscopy [T. Lenzer, I. Yourshaw, M. R. Furlanetto, G. Reiser, and D. M. Neumark, J. Chem. Phys. 110, 9578 (1999)] and various nonadditive terms. The EAs calculated without many-body effects overestimate the experimental EAs by up to 1500 cm−1. Repulsive many-body induction in the anion clusters is found to be the dominant nonadditive effect. In addition, the attractive interaction between the chloride charge and the Ar2 exchange quadrupole is important. These findings are consistent with our earlier results for XenI−, ArnI−, and ArnBr− clusters and highlight again the necessity of an adequate implementation of many-body effects to describe the energetics of such systems. For ArnCl− clusters with n>12 we find some deviations between experimental and calculated (0 K) EA which can be explained by the population of less stable anion structures due to the finite temperatures of the clusters in our experiments. This results in lower EAs than predicted for the corresponding global minimum energy structures.

Versatile behaviour of iron–arylcarbene complexes towards alkoxides: CCl and CC bond activation reactions

The Cp-containing carbene complexes [ Fe(C 5 H 5 )(CO){κ 2(C,O)&0xF700; C(OMe)C 6 H 4-o -O Me}][OTf] ( 2) and [Fe(C 5H 5)(CO)(CH 3CN){C(OMe)C 6H 4- o-Cl}[OTf] ( 3) have been synthesised and characterised. Complex 2 has been characterised by a single-crystal X-ray diffraction analysis; the Fe–O distance of 2.045(5) Å suggests a rather strong bonding of the methoxy group. Substitution of one carbonyl ligand by PPh 3 allows the isolation of the chelate complex [ Fe(C 5 H 5 )(PPh 3){ κ 2(C,Cl)&0xF700; C(OMe)C 6 H 4-o -C l}][OTf] ( 4). The reaction of [ Fe(C 5 Me 5 )(CO){κ 2(C,Cl)&0xF700; C(OMe)C 6 H 4-o -C l}][OTf] ( 5) with alkoxides RONa (R=Me, Et) affords the chelate complexes [ Fe(C 5 Me 5 )(CO){κ 2(C,O)&0xF700; C 6 H 4-o -C(OMe)(O R)(OR)}] 7 (R=Me) and 8 (R=Et), respectively. Similarly, the reaction of 3 with EtONa affords [ Fe(C 5H 5)(CO){κ 2( C, O)−C 6H 4-o-C(O Et)(OEt)2}] ( 9), for which the ArCl bond has been cleaved. No activation of the ArCl bond is observed for the unchelated complex [Fe(C 5Me 5)(CO) 2{C(OMe)C 6H 4- o-Cl}][OTf]. In contrast, treatment of the anisyl derivative [ Fe(C 5 Me 5 )(CO){κ 2(C,O)&0xF700; C(OMe)C 6 H 4-o -O Me}][OTf] ( 6) with EtONa gives selectively the carbene complex [Fe(C 5Me 5)(CO)(C 6H 4- o-OMe){C(OEt) 2}] ( 12). The ArOMe bond remains intact, but cleavage of the CαCAr bond occurs. This rearrangement process, i.e. α-elimination of the anisyl substituent, is favoured by the lability of the ortho-OMe group. Treatment of 2 with NaOEt gives as the only identified compound the ethyl ester [MeOC 6H 4- o-(CO)OEt]. Clean formation of the methyl ester derivative [MeOC 6H 4- o-(CO)OMe] is observed upon oxidation of 2 with C 6H 5I +O −.

A theoretical study of H–Ar–Cl

Ab initio calculations at the B3LYP and MP4(SDQ) levels of theory were performed on the noble gas-containing compound H–Ar–Cl. The calculations indicate that the molecule should be metastable with an activation barrier of 73.0 kJ mol−1 for the lowest-energy fragmentation to HCl and Ar. Similar calculations on H–He–Cl and H–Ne–Cl failed to locate stable species. This result suggests that it should be possible to generate and observe H–Ar–Cl at sufficiently low temperatures.

A Novel Type of Alkynylgold(I) Complex. Crystal and Molecular Structures of PPN[Au(Ar)(C⋮CH)] [Ar = C6F5, C6H2(NO2)3-2,4,6

Complexes of the type PPN[Au(acac)(Ar)] [PPN = (Ph3P)2N, acac = acetylacetonate], obtained in solution from Tl(acac) and the corresponding PPN[Au(Ar)Cl] derivatives after removal of TlCl, react in situ with ethyne to give a new type of ethynylgold(I) complex, PPN[Au(Ar)(C⋮CH)] [Ar = C6F5 (1), C6H4NO2-2 (2), C6H2(NO2)3-2,4,6 (3)]. The crystal structures of 1 and 3 have been determined.

Bromination and nitration reactions of metallated (Ru and Os) multiaromatic ligands and crystal structures of selected products

Three nitrogen-containing aromatic heterocycles, 2-(1′-naphthyl)pyridine, 2-phenylquinoline, and 2,3-diphenylquinoxaline, have been mercurated in the naphthyl or phenyl ring 2-position and then symmetrised to form the mercury compounds Ar 2Hg (Ar=Nppy ( 3), Phqn ( 1) or Dpqx ( 5), respectively). These reagents are suitable for trans-metallation and reaction with MHCl(CO)(PPh 3) 3 affords the complexes M(η 2-C,NAr)Cl(CO)(PPh 3) 2, ( 6, M=Ru, Ar=Nppy; 7, M=Os, Ar=Nppy; 8, M=Ru, Ar=Phqn; 9, M=Os, Ar=Phqn; 10, M=Ru, Ar=Dpqx; 11, M=Os, Ar=Dpqx) in which each product features an aryl ligand that forms a strongly chelated five-membered ring through coordination of the heterocyclic N atom. The chloride ligand in each of the complexes 6– 11 can be replaced by dimethyl dithiocarbamate to give ultimately the mono-triphenylphosphine complexes, M(η 2-Ar)(η 2-S 2CNMe 2)(CO)(PPh 3) ( 12, M=Ru, Ar=Nppy; 13, M=Os, Ar=Nppy; 14, M=Ru, Ar=Phqn; 15, M=Os, Ar=Phqn; 16, M=Ru, Ar=Dpqx; 17, M=Os, Ar=Dpqx). Similarly, compound 10 when treated with Na(acac) gives Ru(η 2-Dpqx)(η 2-acac)(CO)(PPh 3) ( 18), while treatment with trifluoroacetic acid gives Ru(η 2-Dpqx)(O 2CCF 3)(CO)(PPh 3) 2 ( 19). Many of these complexes were found to be very robust, making them suitable for electrophilic aromatic substitution reactions under harsh conditions. In each case, the presence of the metal had both an activating and a directing effect on the aryl ring to which it was bonded. Bromination or nitration reactions, both of which are not normally possible with organometallic substrates, were carried out successfully, giving rise to monobrominated or dinitrated products, respectively. The following compounds were characterised, M(η 2-Ar-4-Br)Cl(CO)(PPh 3) 2 ( 20, M=Ru, Ar=Phqn; 21, M=Os, Ar=Phqn; 22, M=Ru, Ar=Dpqx; 24, M=Os, Ar=Dpqx), M(η 2-Dpqx-4-Br)(η 2-S 2CNMe 2)(CO)(PPh 3) ( 23, M=Ru; 25, M=Os), Os(η 2-Ar)Cl(CO)(PPh 3) 2 ( 26, Ar=Nppy-6,8-(NO 2) 2; 27, Ar=Phqn-4,6-(NO 2) 2). Crystal structures of compounds 7, 12, 15, 18, 19, 21, 23 and 25 have been determined.

An energy-resolved study of the partial fragmentation dynamics of Ar–HCl into H+Ar–Cl after ultraviolet photodissociation

The UV photolysis of Ar–HCl is simulated by an exact wave packet calculation. Partial fragmentation of the cluster into H and Ar–Cl fragments is studied by projecting out the asymptotic wave packet onto the product states, at several excitation energies in the range of the Ar–HCl absorption spectrum. The partial fragmentation pathway is found to dominate the photolysis process at very low excitation energies, and to be intense also at high energies. At medium excitation energies the other competing fragmentation pathway, namely total fragmentation into H, Ar, and Cl, dominates almost completely the photodissociation dynamics. The relative intensity of the two fragmentation pathways depends on the extent to which the hydrogen is initially blocked by Ar and Cl. The Ar–Cl radicals are produced with high rotational and low vibrational excitation at most of the Ar–HCl energies studied. The internal energy distributions of Ar–Cl show remarkable differences in shape depending on the regions of the absorption spectrum which are excited. This effect can be exploited to control both the efficiency of Ar–Cl generation and the internal excitation of the radical prepared, by changing the excitation energy of the parent cluster.

Preparation and probing of Ar–Cl radical complexes from UV photodissociation of the Ar–HCl cluster

Photodissociation of Ar–HCl is simulated by exact wavepacket calculations. The asymptotic wavepacket is projected out onto the product states corresponding to several excitation energies of Ar–HCl. A high relative efficiency of Ar–Cl formation is found at low and high cluster excitation energies. The ro-vibrational state distribution of the Ar–Cl radical formed is reflected in the kinetic-energy distribution of the H fragment. Photolysis of Ar–HCl then appears as an efficient method for preparing Ar–Cl radicals, simultaneously probing their final state distribution.

Hemilabile Properties of Chelate Iron Complexes: Synthesis and Structure of Oxametallacycles

Oxametallacycles [Fe(C5Me5)(CO){C3(C6H4-o-Cl)(CO2Me)(R)Oa}(Fe–Oa)] (2, R = OMe; 4, R = Me) are accessible from the chelate (chloroaryl)carbene complex [Fe(C5Me5)(CO){C(OMe)C6H4-o-Cla}(Fe–Cla)][OTf] (1) upon treatment with the appropriate carbanions. Their formation arises from the lability of the chlorine atom. The related phosphonium salt [Fe(C5Me5)(CO){C3(C6H4-o-PMe3)(CO2Me)(OMe)Oa}(Fe–Oa)][OTf] (3) is formed only for the bis(ester) derivative, via Ar–Cl bond activation. No reaction occurs for 4, for which the coordination of the acetyl group has been supported by an X-ray analysis.

On the Mechanism of C−H Bond Activation in the Photochemical Arylation of Rhenium(V) Oxo Iodide Complexes

Photolysis of the Re(V) oxo−iodide compound (HBpz3)ReO(I)Cl (1) in arene solvents gives the aryl complexes (HBpz3)ReO(Ar)Cl. Substituted arenes react with electrophilic selectivity exclusively at aromatic C−H bonds, and a variety of functional groups are tolerated. Yields are improved when photolysis is carried out in the presence of pyridine. Photolysis of the diiodide complex, (HBpz3)ReOI2 (2), gives a mixture of mono- and disubstituted Re−aryl complexes, and the diphenyl derivative (HBpz3)ReOPh2 has been structurally characterized. The isotope effect found when 1 is photolyzed with a 1:1 mixture of C6H6 and C6D6 was found to depend on the concentration of 1. Lower concentrations (∼0.5 mM) show a 1.2(2):1 ratio of d0 to d5 products, while higher concentrations (∼20 mM) show higher d0:d5 ratios of 1.8(2):1. The apparent isotope effects increase with increasing conversion and are also affected by the presence of additives such as pyridine or iodine. Photolysis of 1 with 1,3,5-trideuteriobenzene shows a 4.0(4):1 ratio of C−H vs C−D activation, which is independent of reaction conditions. A mechanism for arene activation is proposed that involves initial arene binding, which discriminates intermolecularly between arenes with a low isotope effect, followed by C−H bond cleavage, which discriminates intramolecularly within an arene with a higher isotope effect. The reactive species appears to be a rhenium(IV) oxo complex which can add aromatic C−H bonds across the ReO linkage.

Influence of the atom–atom interaction anisotropy on the structure and stability of Ar nCl 2 clusters

Global potential energy minima have been characterized for Ar n Cl 2 clusters ( n = 2 to 25) using a simple sum of Ar–Ar and Ar–Cl 2 potentials. We compare the results for a fully anisotropic (double-minimum) Ar–Cl 2 interaction, obtained from scaled high-level ab initio calculations, with those for an approximate (single-minimum) form involving equivalent isotropic ArCl terms. Many of the global minima, with some interesting exceptions, can be understood in terms of low-lying minima of Ar n+2 . In particular, several global minima exhibit unusual six-fold axial symmetry for the more realistic fully anisotropic form. The approximate isotropic potential does not support some global minima which the fully anisotropic form predicts to have high relative stability. The effect of three-body forces between Ar atoms is shown to be generally unimportant.

Selective Activation of Ar-Cl and Ar-C Bonds with Iron(II) Complexes.

The electrophilic iron-carbene chelate complexes 1 and 2 react with alkoxides RO- to give the neutral chelate complex 3 and the carbene complex 4, respectively. Depending on the nature of the chelating ortho substituent, selective activation of the Ar-Cl or Ar-C bond occurs; these processes are promoted by the chelation.

Study of the total and partial fragmentation dynamics of Ar–HCl after uv photodissociation

The uv photolysis of the Ar–HCl cluster is studied applying an exact time-dependent wave packet method in three dimensions, assuming zero-total angular momentum. The photodissociation process is found to occur via two different fragmentation mechanisms, depending on the initial excitation energy of the cluster. One mechanism leads to total dissociation of the complex, producing three fragments, Ar–HCl+hν→H+Ar+Cl. The fragmentation dynamics in this case is governed by resonance states at relatively low energies of the cluster, in which the H atom collides a number of times with Ar and Cl before dissociating. Manifestations of these collisions are found in the final kinetic energy distribution of the photofragments, which is redshifted in the case of the H fragment, and blueshifted in the Ar and Cl cases. The second type of mechanism consists of a fast and direct photodissociation of the hydrogen, leading to a partial fragmentation of Ar–HCl into hot H fragments and bound Ar–Cl radical molecules. This mechanism dominates at higher energies, which are those mostly populated by the wave packet initially prepared in the present calculations. The experimental implications of the results are discussed.

Inclusion of ion-pair states in the diatomics-in-molecules description of potential energy surfaces: van der Waals complexes of HeCl 2 and ArCl 2

It is shown that the inclusion of excited ionic configurations in the diatomics-in-molecules (DIM) Hamiltonian serves as a natural means to account for main features of non-additivity in three-body potential energy surfaces of HeCl 2 and ArCl 2 van der Waals complexes. For ground state Cl 2( 1Σ g), while consideration of only neutral configurations leads toT-shaped isomers, inclusion of the excited Cl +Cl −1 configuration stabilizes the linear isomer and destabilizes the T-shaped isomer. Within the same formalism, the excited Cl 2( 3Π) only sustains minima in the T-shaped isomer. Potential energy surfaces created with a minimal DIM basis are constructed and shown to compare favorably with the most accurate ab initio surfaces and experiments. Analytical forms are given for three-body surfaces, meant for fitting purposes and as a convenience in simulations of dynamics.